Aav vectors for treatment of dominant retinitis pigmentosa

ABSTRACT

Aspects of the disclosure relate to methods and compositions for treating retinitis pigmentosa. In some aspects, the disclosure provides compositions and methods for delivering an interfering nucleic acid (for example an interfering RNA) to a subject in order to reduce expression of one or both alleles of an endogenous rho gene (for example a mutant rho allele associated with retinitis pigmentosa) in the subject. In some embodiments, a replacement rho gene that is resistant to the interfering nucleic acid also is delivered to the subject.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/302,122, filed Mar. 1, 2016, and U.S. ProvisionalPatent Application No. 62/398,451, filed Sep. 22, 2016, the contents ofeach of which are incorporated herein by reference in their entireties.

GOVERNMENT SUPPORT

This invention was made with government support under grant numberR24-EY022012 awarded by the National Institutes of Health. Thegovernment has certain rights in the invention.

BACKGROUND

Autosomal dominant retinitis pigmentosa (adRP) is a blinding diseaseaffecting 1 in 12,000 people. A sizeable fraction of these individualscarry a mutation in the gene (rho) for rhodopsin, the light harvestingpigment protein of the photoreceptor cells in the retina. The disease isdominant because inheritance of the mutated gene from either parentleads to retinal degeneration and eventual blindness. Over 100 differentmutations identified in rho lead to blindness. There is currently noapproved drug or gene therapy treatment for adRP. Thus, there is a needfor effective treatment options pertaining to any and all causes of adRPand related conditions.

SUMMARY

Aspects of the application relate to compositions and methods fortreating retinitis pigmentosa (e.g., dominant retinitis pigmentosa) in asubject (e.g., in a human). In some embodiments, one or both alleles ofthe rhodopsin gene (rho gene) of a subject are silenced by administeringan interfering RNA molecule to a subject (e.g., to a subject havingretinitis pigmentosa, for example to a human having dominant retinitispigmentosa). In some embodiments, a replacement rho gene also isadministered to the subject to provide a functional RHO protein torestore photoreceptor function to the subject. In some embodiments, thereplacement rho gene has one or more nucleotide substitutions relativeto the endogenous gene allele(s) that render the replacement generesistant to the effects of the interfering RNA. In some embodiments,the replacement rho gene is a human rho gene (e.g., a wild-type humanrho gene) that includes one or more (e.g., 1, 2, 3, 4, 5, or more)substitutions to render the gene resistant (also referred to as“hardened”) to degradation mediated by the interfering RNA molecule. Insome embodiments, the one or more nucleotide substitutions are in thecoding sequence of the rho gene. In some embodiments, the one or morenucleotide substitutions are silent (e.g., they do not alter the aminoacid sequence of the RHO protein). In some embodiments, the one or moresubstitutions introduce an amino acid change, but the resulting RHOprotein is still sufficiently functional to be therapeutically effective(to restore or maintain at least partial sight, or normal sight).

In some embodiments, an interfering RNA and/or a replacement gene can bedelivered to a subject using any suitable technique. In someembodiments, an interfering RNA is provided to a subject in the form ofa gene that encodes the interfering RNA. In some embodiments, the genethat encodes the interfering RNA is provided to the subject in arecombinant adeno-associated virus (rAAV). In some embodiments, thereplacement gene is provided to the subject in an rAAV. In someembodiments, the gene that encodes the interfering RNA and thereplacement gene are provided in the same rAAV (for example they areboth encoded on the same recombinant genome flanked by AAV invertedterminal repeats (ITRs)). In some embodiments, both genes are undercontrol of the same promoter. In some embodiments, the genes are underthe control of two different promoters. In some embodiments, the genethat encodes the interfering RNA and the replacement gene are providedin different rAAVs.

In some embodiments, the interfering RNA is a synthetic ribonucleic acid(RNA) molecule comprising:

a) a sense strand of sequence CUGCCUACAUGUUUCUGCU (SEQ ID NO: 1) and anantisense strand of sequence AGCAGAAACAUGUAGGCAG (SEQ ID NO: 2);

b) a sense strand of sequence CCUACAUGUUUCUGCUGAU (SEQ ID NO: 3) and anantisense strand of sequence AUCAGCAGAAACAUGUAGG (SEQ ID NO: 4);

c) a sense strand of sequence GCAUGGUCAUCAUCAUGGU (SEQ ID NO: 5) and anantisense strand of sequence ACCAUGAUGAUGACCAUGC (SEQ ID NO: 6); or

d) a sense strand of sequence GUGGCAUUCUACAUCUUCA (SEQ ID NO: 7) and anantisense strand of sequence UGAAGAUGUAGAAUGCCAC (SEQ ID NO: 8).

In some embodiments, the synthetic RNA molecule is a small interferingRNA (siRNA).

In some embodiments, the interfering RNA is a small hairpin RNA (shRNA).In some embodiments, the shRNA comprises a loop having an RNA ofsequence UCAAGAG (SEQ ID NO: 9) or RNA of sequence UGUGCUU (SEQ ID NO:10).

In some embodiments, the synthetic RNA molecule is an artificial microRNA (miRNA). In some embodiments, the artificial miRNA has an RNAsequence of:

(SEQ ID NO: 19) UGCUGUUGACAGUGAGCGA(X)_(n)UAGUGAAGCCACAGAUGUA(Y)_(n)CUGCCUACUGCCUCGGA,wherein:

a) (X)_(n) comprises SEQ ID NO: 1 and (Y)_(n) comprises SEQ ID NO: 2;

b) (X)_(n) comprises SEQ ID NO: 3 and (Y)_(n) comprises SEQ ID NO: 4;

c) (X)_(n) comprises SEQ ID NO: 5 and (Y)_(n) comprises SEQ ID NO: 6; or

d) (X)_(n) comprises SEQ ID NO: 7 and (Y)_(n) comprises SEQ ID NO: 8.

In some embodiments, a synthetic RNA described above or elsewhere inthis application further comprises an unpaired overhang sequence at the5′ and/or 3′ end. In some embodiments, the unpaired overhang sequencecomprises a sequence of repeating bases. In some embodiments, thesequence of repeating bases comprises repeating uracil (U) bases. Insome embodiments, the unpaired overhang sequence is UU.

In some embodiments, a composition (e.g., a composition foradministration to a subject) comprises one or more (e.g., 2, 3, or 4) ofthe interfering RNAs (e.g., synthetic RNA molecules) described above orelsewhere in this application. In some embodiments, a composition (e.g.,a composition for administration to a subject) comprises a nucleic acid(e.g., a DNA) that encodes one or more (e.g., 2, 3, or 4) of theinterfering RNAs (e.g., synthetic RNA molecules) described above orelsewhere in this application.

In some embodiments, a composition also includes one or morephysiologically acceptable carriers and/or one or more physiologicallyacceptable adjuvants.

In some embodiments, a vector encodes one or more (1, 2, 3, or 4, ormore) shRNAs and/or artificial miRNAs (e.g., described above orelsewhere herein). In some embodiments, the shRNAs have a sequence ofone or more of SEQ ID NOs: 11-18.

In some embodiments, a vector encodes a replacement rho gene.

In some embodiments, a vector encodes a replacement rho gene and/or oneor more shRNAs and/or artificial miRNAs (e.g., described above orelsewhere herein).

In some embodiments, the vector is an expression plasmid. In someembodiments, the vector is a recombinant viral genome (e.g., an rAAVgenome). In some embodiments, the vector is a viral vector. In someembodiments, the viral vector comprises an rAAV genome.

In some embodiments, a method of decreasing RHO expression in a subjectincludes administering to the subject a composition including one ormore interfering RNAs and/or one or more vectors each encoding (e.g.,capable of expressing) one or more interfering RNAs described above orelsewhere herein.

In some embodiments, a method of treating retinitis pigmentosa (RP) in asubject includes administering to the subject both a compositioncomprising an interfering RNA or a vector expressing an interfering RNAand a composition comprising a recombinant rho gene (for example avector encoding the recombinant rho gene), wherein the rho gene isresistant to targeting by the interfering RNA.

In some embodiments, the recombinant rho gene is delivered using anrAAV. In some embodiments, the interfering RNA and the recombinant rhogene are delivered using the same rAAV. In some embodiments, theinterfering RNA and the recombinant rho gene are both under expressioncontrol of a single promoter sequence. In some embodiments, theinterfering RNA and the recombinant rho gene are each under expressioncontrol of independent promoter sequences (e.g., either constitutive orinducible promoters). In some embodiments, the interfering RNA and/ormodified rho gene are under expression control of (e.g., operativelyconnected to) a human promoter or a promoter of a different species(e.g., a viral promoter, a prokaryotic promoter, or a eukaryoticpromoter, for example, a promoter from a non-human primate, a rodent, adog, a cat, a pig, or other species). In some embodiments, a promoter isan RNA polymerase III promoter (e.g., H1 RNA polymerase III promoter) oran RNA polymerase II promoter, or an RNA polymerase I promoter. In someembodiments, the interfering RNA is shRNA, and the shRNA is underexpression control of an RNA polymerase III promoter (e.g., H1 RNApolymerase ITT promoter). In some embodiments, the interfering RNA is anartificial miRNA, and the artificial miRNA is under expression controlof an RNA polymerase II promoter. In some embodiments, the recombinantrho gene is under expression control of a constitutive or induciblepromoter (e.g., a human promoter, an eye-specific promoter). In someembodiments, the constitutive or inducible promoter is a mouse promoter(e.g., a mouse opsin (MOPS) promoter).

In some embodiments, the subject is a mammal. In some embodiments, themammal is a rodent or a dog. In some embodiments, the mammal is a human(e.g., a human having or known to have, for example diagnosed as having,retinitis pigmentosa, for example dominant retinitis pigmentosa). Theseand other aspects are described in the following drawings, examples, andclaims.

BRIEF DESCRIPTION OF DRAWINGS

The drawings and following brief descriptions provide non-limitingexamples of aspects of the compositions and methods described herein.

FIG. 1A-C shows knockdown of GFP tagged human rhodopsin measured by FACS(fluorescence-activated cell sorting). This experiment was performed in293T cells with three biologic replicates. 500 ng of GFP-Tagged humanRHO cDNA was co-transfected with different siRNAs. Transfections wereperformed utilizing LIPOFECTAMINE® 2000 transfection reagent. Thecontrol was a non-targeting siRNA purchased from Dharmacon. Samples wereincubated for 72 hours and then analyzed by flow cytometry, first gatedfor Forward and Side scatter to exclude non-viable particles then forGFP expression above autofluorescence. The number of GFP positive cellstreated with the control siRNA was set to 100%.

FIG. 2 shows RHO knockdown by shRNA. This experiment was performed in293T cells with three biologic replicates. 200 ng of GFP-tagged humanrhodopsin was co-transfected with pUC57 containing either shRNA 131,765, or 820 driven by the H1 promoter. Samples were incubated for 72hours and RHO knockdown measured by flow cytometry as in FIG. 1.

FIG. 3 shows that shRNAs cleave both mutant and wild type RHO RNA. Thisexperiment was performed in 293T cells with two biologic replicates andthree qRT-PCR replicates. 200 ng of GFP-tagged human rhodopsin (WT, T17Mor P23H) was co-transfected with rAAV-H1-shRNA plasmids (131 (SEQ ID NO:11). 765 (SEQ ID NO: 15), or 820 (SEQ ID NO: 17)) utilizingLIPOFECTAMINE® 2000. The Non-Targeting shRNA was designed to degrade anunrelated phototransduction protein, a subunit of the rod cyclic GMPgated ion channel. Samples were incubated for 48 hours then processedfor qRT-PCR analysis.

FIG. 4 shows siRNA 131 sense (SEQ ID NO: 1) and antisense (SEQ ID NO: 2)strands in the sequence context of miR30 (SEQ ID NO: 28). Afterexpression from an RNA polymerase II promoter, the siRNA will be excisedfrom the precursor by the enzyme Drosha in the nucleus and Dicer in thecytoplasm.

FIGS. 5A-5C show (FIG. 5A) a rhodopsin immunoblot in biopsy punchestaken from bleb and non-bleb areas of canine retina. FIG. 5B showsquantitation of rhodopsin monomer amounts, normalized to histone. FIG.5C is a table showing the normalized amounts.

FIGS. 6A-6B show the absolute numbers of canine RHO RNA. FIG. 6A is aplot of the absolute numbers of canine RHO RNA. FIG. 6B is a tableshowing the absolute RNA numbers.

FIGS. 7A-7C show (FIG. 7A) a rhodopsin immunoblot in biopsy punchestaken from bleb and non-bleb areas of canine retina. FIG. 7B showsquantitation of rhodopsin monomer amounts, normalized to histone. FIG.7C is a table showing the normalized amounts.

FIGS. 8A-8B show the absolute numbers of canine RHO RNA. FIG. 8A is aplot of the absolute numbers of canine RHO RNA. FIG. 8B is a tableshowing the absolute RNA numbers.

FIG. 9 depicts exemplary base pairing that occurs between shRNA and thetarget sequence of endogenous human or hardened RHO mRNA. All shRNAsbase-pair perfectly with the target sequence of RHO mRNA of dog. Whitebox: mismatch between shRNA and endogenous dog as well as hardened RHOmRNA. Dark gray box: a weak wobble base pairing that occurs in RNAbetween guanosine and uracil. Light gray box: mismatch between shRNA andhardened RHO mRNA only. Sequences correspond to SEQ ID NOs: 29-37 fromtop to bottom, respectively.

FIG. 10 depicts exemplary base pairing that occurs between shRNA134 andthe target sequence of endogenous human or hardened RHO131 mRNA. Theproximity of the target sequences of shRNAs 131 and 134 enables the samehardened RHO131 to be employed. Dark gray box: a weak wobble basepairing that occurs in RNA between guanosine and uracil. Light gray box:mismatch between shRNA and hardened RHO mRNA only. Sequences correspondto SEQ ID NOs: 38-40 from top to bottom, respectively.

FIG. 11 depicts an exemplary map of a plasmid encoding GFP-tagged humanRHO.

FIGS. 12A-12C shows non-limiting examples of maps of plasmids encodingsiRNA (FIGS. 12A and 12B) and human RHO (FIG. 12C).

FIGS. 13A-13E show RNA and protein analysis of rhodopsin knockdown withdifferent viral titers of AAV2/5-sc-H1-shRNA820 injected subretinally inWT RHO^(+/+) dogs. FIG. 13A shows retinal maps showing position ofbiopsy punches used for western blot analysis and RNA quantitation.Paired dark gray, gray and dotted circles indicate the position ofbiopsy punches in the bleb/treated and non-bleb/untreated regions foreach replication of western blot, whereas the black circles indicate thepositions of biopsy punches for RNA quantitation. FIG. 13B shows a bargraph showing remaining canine Rhodopsin RNA in the treated area as apercentage of levels measured in the untreated area of the same retina.FIG. 13C shows immunoblot showing the amount of Rhodopsin in biopsypunches taken from treated (Tx) and untreated (UnTx) areas of canineretina. Histone H3 was used for normalization. Bar graphs show remainingcanine Rhodopsin protein as a percentage of levels measured in theuntreated area of the same retina. FIG. 13D is a table showing numericalvalues from each experiment reported as a percentage of RNA or proteinremaining. FIG. 13E is another table showing the numerical values fromeach experiment reported as percent knockdown of RNA or protein.

FIGS. 14A-14D show the assessment of ONL and ELM/IS/OS integrityfollowing subretinal injection of different titers ofAAV2/5-sc-H1-shRNA820 in WT dogs. FIG. 14A shows ONL thickness maps;FIG. 14B shows ELM/IS/OS maps of normalized intensity; FIG. 14C showsONL thickness values; and FIG. 14D shows values of normalized intensityof the ELM/IS/OS layers.

FIGS. 15A-15E show RNA and protein analysis of rhodopsin knockdown withdifferent viral titers of AAV2/5-se-H1-shRNA820 injected subretinally inmutant RHOT^(T4R/+) dogs. FIG. 15A shows retinal maps showing positionof biopsy punches used for western blot analysis and RNA quantitation.Paired dark gray, gray and dotted circles indicate the position ofbiopsy punches in the bleb and non-bleb region for each replication ofwestern blot, whereas the black circles indicate the position of biopsypunches for RNA quantitation. FIG. 15B is a bar graph showing the amountof remaining canine Rhodopsin RNA as a percentage of levels measured inthe untreated area of the same retina. FIG. 15C is an immunoblot showingthe amount of canine Rhodopsin in biopsy punches taken from treated (Tx)and untreated (UnTx) areas of canine retina. Histone H3 was used fornormalization. Bar graphs show the amount of remaining canine Rhodopsinprotein as a percentage of levels measured in the untreated area of thesame retina. FIG. 15D is a table showing numerical values from eachexperiment reported as a percentage of RNA or protein remaining. FIG.15E is another table showing the numerical values from each experimentreported as percent knockdown of RNA or protein.

FIGS. 16A-16D show OCT B scans encompassing the treated (with differentviral titers of AAV2/5-sc-H1-shRNA820) and untreated retinal areas ofRHO^(T4R/+) dogs 2 weeks following exposure to a brief dose of lightthat causes acute retinal degeneration in mutant RHO^(T4R/+) dogs. (FIG.16A) OCT scan of a dog treated with 1×10¹² vg/ml. (FIG. 16B) OCT scan ofa dog treated with 5×10¹¹ vg/ml. (FIG. 16C) OCT scan of a dog treatedwith 2.5×10¹¹ vg/ml. (FIG. 16D) OCT scan of a dog treated with 1×10¹¹vg/ml.

FIGS. 17A-17B show topographic map ONL thickness from a RHO^(T4R/+)treated with AAV2/5-sc-H1-shRNA820 showing protection from light-inducedretinal degeneration. (FIG. 17A) ONL thickness map of an untreated WTcontrol dog (left panel), and ONL thickness map of EM411-OS treated withAAV2/5-sc-H1-shRNA820 at 5E+11 vg/ml and showing preserved ONL thicknessin the treated/bleb region weeks after light-induced damage. Black andwhite curve shows the limits of the bleb as seen immediately after thesubretinal injection. Panels below show OCT B scans with ONL colored indarker gray (middle band) for visualization purposes. (FIG. 17B) Locioutside and inside the bleb were selected for ONL thicknessmeasurements.

FIG. 18 shows histology (H&E stained) and immunohistochemistry(Rhodopsin was stained in green and appears as light staining in thelower panels of FIG. 18; human cone arrestin was stained in red andappears as gray staining in the lower panels of FIG. 18) in the treated(Tx) and Untreated (UnTx) areas of mutant RHO^(T4R/+) retinassubretinally with different viral titers AAV2/5-sc-H1-shRNA820.

FIGS. 19A-19F show RNA and protein analysis of rhodopsin knockdown andreplacement with AAV2/5-sc-HOP-RHO820-H1-shRNA820 injected subretinallyin mutant RHO^(T4R/+) dogs at 5×10¹¹ vg/ml titer. FIG. 19A shows retinalmaps showing position of biopsy punches used for western blot analysisand RNA quantitation. Paired dark gray, gray and dotted circles indicatethe position of biopsy punches in the treated (Tx) and untreated (UnTx)regions for each replication of western blot, whereas the black circlesindicate the position of biopsy punches for RNA quantitation. FIG. 19Bshows immunoblot showing the amount of total rhodopsin (canine+humanRHO820) in biopsy punches taken from treated (Tx) and untreated (UnTx)areas of canine retina. Histone H3 was used for normalization. Bargraphs show the percentage of remaining rhodopsin protein in the Treatedand untreated areas. Note the loss of the lower MW band (correspondingto mutant T4R RHO protein) in the treated areas of EM424-OD andEM425-OD. FIG. 19C is a table showing numerical values for each pair ofpunches used for protein quantification. FIG. 19D is a bar graph showingremaining canine Rhodopsin RNA in the treated areas as a percentage ofcanine RHO RNA levels measured in untreated areas. FIG. 19E is a bargraph showing levels of human RHO820 in the treated areas as apercentage of canine RHO RNA levels measured in untreated areas. FIG.19F is a table showing numerical values for each pair of punches usedfor RNA quantification.

FIGS. 20A-20C show in vivo retinal imaging showing protection fromlight-induced retinal degeneration in the region of a mutant RHO^(T4R/+)retina treated with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹ vg/mltiter. FIG. 20A shows en face cSLO composite showing 2 weeks post lightexposure the retinal region (border demarcated by white arrows) that wasprotected from degeneration. Light gray arrow indicates the locationwithin the treated area of the OCT B scans shown in FIG. 20B, dark grayarrow indicates the location within the untreated area of the OCT Bscans shown in FIG. 20C. FIG. 20B shows OCT B scans within the treatedarea before injection, 11 weeks post injection, and 13 weeks postinjection/2 weeks post light exposure. ONL thickness is preservedthroughout the treated area at both time-points following the injectionof the viral vector. FIGS. 20B and 30V show OCT B scans within theuntreated area before injection, 11 weeks post injection, and 13 weekspost injection/2 weeks post light exposure. ONL is preserved up to 11weeks post injection but is completely lost 2 weeks after lightexposure.

FIG. 21 shows topographic maps of ONL thickness from a two RHO^(T4R/+)treated with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹ vg/ml titershowing protection from light-induced retinal degeneration.

FIG. 22 shows immunohistochemistry (Rhodopsin was stained in green andappears as light staining in the panels of FIG. 22; human cone arrestinwas stained in red and appears as gray staining in the panels of FIG.22) in the treated, transition zone and untreated areas of mutantRHO^(T4R/+) retinas subretinally injected withAAV2/5-sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹ vg/ml titer.

DETAILED DESCRIPTION

Aspects of the application provide methods and compositions that areuseful for treating retinitis pigmentosa in a subject (e.g., in asubject having dominant retinitis pigmentosa).

In some embodiments, the expression of endogenous rhodopsin (e.g.,mutant and normal) is reduced or suppressed using RNA interference, andthe missing protein is replaced by delivering a gene for the normalprotein that is engineered to remove the target site for the RNAinhibitor.

In some embodiments, a single adeno-associated virus (AAV) vector isused to deliver both the RNA agent (e.g., small hairpin RNA orartificial microRNA) and the recombinant RHO gene.

In some embodiments, small hairpin RNAs, artificial microRNAs (a-miRs)and/or RNA enzymes (ribozymes) can be designed to degrade rhodopsin mRNAby targeting sequences that are common in mouse, human, and dog. Suchmolecules can be useful to test inhibition in cell culture, in mice,and/or in dogs, to develop inhibitors that can work in human patients.

In some embodiments, small interfering nucleic acids (e.g., RNAs) areprovided that target both human and dog rhodopsin mRNA. In someembodiments, four small interfering to RNAs that digest human and caninerhodopsin (RHO) mRNA are provided for the purpose of depletingendogenously made rhodopsin in humans and animals. In some embodiments,these interfering RNAs target rhodopsin expression in subjects having adominant inherited form of retinitis pigmentosa caused by mutations inRHO. Some of these mutations lead to a toxic form of the protein, thesynthesis of which must be silenced to prevent degeneration of theretina.

In some embodiments, an interfering nucleic acid (e.g., RNA) is designedto target a sequence that is specific for a mutant rho gene (e.g., it iscomplementary to a sequence that is present in the mutant rho gene andnot present in a wild-type rho gene). However, in some embodiments aninterfering nucleic acid is designed to target a wild-type sequence in amutant endogenous rho gene (e.g., having one or more mutations at otherpositions not targeted by the interfering nucleic acid). In furtherembodiments, a functional (e.g., wild-type) rho gene that is resistantto the interfering nucleic acid is provided to restore RHO activity inthe subject and thereby treat one or more symptoms of a disease ordisorder associated with the mutant endogenous rho allele(s) that is/aretargeted by the interfering nucleic acid.

In some embodiments, one or more of the interfering RNAs can bedelivered using an adeno-associated virus (AAV) vector either as shorthairpin RNAs (shRNAs) driven by a promoter (e.g., an RNA polymerase IIIpromoter or other suitable constitutive or inducible promoter) or asartificial microRNAs (miRNAs) driven by a promoter (e.g., using an RNApolymerase II promoter or other suitable constitutive or induciblepromoter).

In some embodiments, the same vector expresses a gene (cDNA) thatencodes normal rhodopsin but is resistant to the action of the siRNAexpressed by the virus.

Non-limiting examples of interfering RNAs are provided in Tables 1-4.

TABLE 1 Small interfering RNA (siRNA) SEQ ID NO: Name RNA sequence 1RHO131-S CUGCCUACAUGUUUCUGCU 2 RHO131-A AGCAGAAACAUGUAGGCAG 3 RHO134-SCCUACAUGUUUCUGCUGAU 4 RHO134-A AUCAGCAGAAACAUGUAGG 5 RHO765-SGCAUGGUCAUCAUCAUGGU 6 RHO765-A ACCAUGAUGAUGACCAUGC 7 RHO820-SGUGGCAUUCUACAUCUUCA 8 RHO820-A UGAAGAUGUAGAAUGCCAC

TABLE 2 Hairpin loop RNA SEQ ID NO: RNA sequence 9 UCAAGAG 10 UGUGCUU

TABLE 3 Small hairpin RNA (shRNA) SEQ ID NO: Name RNA sequence 11RHO131-9 CUGCCUACAUGUUUCUGCUUCAAGAGAGCAGAAAC AUGUAGGCAG 12 RHO131-10CUGCCUACAUGUUUCUGCUUGUGCUUAGCAGAAAC AUGUAGGCAG 13 RHO134-9CCUACAUGUUUCUGCUGAUUCAAGAGAUCAGCAGA AACAUGUAGG 14 RHO134-10CCUACAUGUUUCUGCUGAUUGUGCUUAUCAGCAGA AACAUGUAGG 15 RHO765-9GCAUGGUCAUCAUCAUGGUUCAAGAGACCAUGAUG AUGACCAUGC 16 RHO765-10GCAUGGUCAUCAUCAUGGUUGUGCUUACCAUGAUG AUGACCAUGC 17 RHO820-9GUGGCAUUCUACAUCUUCAUCAAGAGUGAAGAUGU AGAAUGCCAC 18 RHO820-10GUGGCAUUCUACAUCUUCAUGUGCUUUGAAGAUGU AGAAUGCCAC

TABLE 4 Micro RNA (miRNA) SEQ ID NO: Name RNA sequence 19 miR30UGCUGUUGACAGUGAGCGA(X)_(n)UAGUGAAGCCACAGAU GUA(Y)_(n)CUGCCUACUGCCUCGGA**X and Y are, independently, any base chosen from A, U, C, or G;(X)_(n), corresponds to a sense strand sequence of n bases and (Y)_(n)corresponds to an antisense strand sequence of n bases.

In some embodiments, a normal (e.g., wild-type) rhodopsin (rho) genethat is hardened can have a sequence based on the human rho gene (e.g.,having a sequence shown in Accession No. NG_009115.1; also shown in SEQID NO: 41) or the mRNA or a protein coding portion thereof (e.g., anmRNA that is encoded by nucleotides 5001-5456 joined to 7238-7406 joinedto 8613-8778 joined to 8895-9134 joined to 9970-11706 of SEQ ID NO: 41or a protein coding portion thereof, for example the coding sequencethat consists of nucleotides 5096-5456 joined to 7238-7406 joined to8613-8778 joined to 8895-9134 joined to 9970-10080 of SEQ ID NO: 41). Insome embodiments, the sequence of a normal rho gene is modified toinclude one or more (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10 or more) mutationsthat render the replacement rho gene resistant to one or moreinterfering RNAs that are being used as knockdown agent(s) to reduceexpression of the mutant endogenous rho gene in a subject being treated.However, in some embodiments, a recombinant rho gene that has a normal(e.g., wild-type) sequence that is not modified can be used if it has adifferent sequence than the endogenous rho gene or allele(s) that is/aretargeted in the subject being treated, and if the knockdown agents beingused are designed to target the endogenous rho gene or allele(s) and notthe recombinant rho gene being provided. In some embodiments, a rho genefrom a different species than the subject being treated can be used.However, in some embodiments, a the rho gene (e.g., a modified rho gene)can be from the same species as the subject being treated. In someembodiments, the one or more modifications in the recombinant rho genealter the nucleic acid sequence of the coding sequence, but do not alterthe encoded protein (e.g., they are silent mutations, for example, atthe third position of a codon that can include one of two or moredifferent nucleotides without changing the encoded amino acid). In someembodiments, a recombinant rho gene does not include the intronsequences of a wild-type rho gene. In some embodiments, a recombinantrho gene encodes an mRNA (or a protein coding portion thereof) of a rhogene that has been modified to be resistant to an interfering RNA. Insome embodiments, a recombinant rho gene includes a wild-type codingsequence that has been modified to be resistant to an interfering RNA.In some embodiments, the modified wild-type coding sequence is providedalong with upstream and/or downstream mRNA sequences that are notderived from the wild-type rho mRNA. In some embodiments, therecombinant replacement rho gene comprises SEQ ID NO: 42. SEQ ID NO: 42(shown below) encodes a portion of an mRNA sequence that is resistant toan example of an interfering RNA referred to as 820 (e.g., siRNA820 orshRNA820 as described herein). An 820 interfering RNA sequence describedherein targets a corresponding sequence in endogenous human rho mRNA asillustrated in FIG. 9, but SEQ ID NO: 42 includes four substitutions(underlined and in bold below, that correspond to positions 9014, 9017,9020 and 9023 of SEQ ID NO: 41) that render it resistant to targeting byan 820 interfering RNA. The coding sequence in SEQ ID NO: 42 starts atposition 88 of SEQ ID NO: 42. In some embodiments, the recombinant rhogene being delivered can include the coding sequence of SEQ ID NO: 42(e.g., starting at position 88 of SEQ ID NO: 42) but with a differentupstream mRNA sequence. In some embodiments, a recombinant rho gene canhave one or more other sequence modifications (either in addition to oras alternatives) to make it resistant to additional or alternativeinterfering RNAs (e.g., other interfering RNAs for which sequences areprovided herein). In some embodiments, one or more interfering RNAs thattarget different regions of the endogenous rho coding sequence in asubject can be used.

SEQ ID NO: 42 (non-limiting example of a modified “hardened” recombinant human rho gene):CCAGCTGGAGCCCTGAGTGGCTGAGCTCAGGCCTTCGCAGCATTCTTGGGTGGGAGCAGCCACGGGTCAGCCACAAGGGCCACAGCCATGAATGGCACAGAAGGCCCTAACTTCTACGTGCCCTTCTCCAATGCGACGGGTGTGGTACGCAGCCCCTTCGAGTACCCACAGTACTACCTGGCTGAGCCATGGCAGTTCTCCATGCTGGCCGCCTACATGTTTCTGCTGATCGTGCTGGGCTTCCCCATCAACTTCCTCACGCTCTACGTCACCGTCCAGCACAAGAAGCTGCGCACGCCTCTCAACTACATCCTGCTCAACCTAGCCGTGGCTGACCTCTTCATGGTCCTAGGTGGCTTCACCAGCACCCTCTACACCTCTCTGCATGGATACTTCGTCTTCGGGCCCACAGGATGCAATTTGGAGGGCTTCTTTGCCACCCTGGGCGGTGAAATTGCCCTGTGGTCCTTGGTGGTCCTGGCCATCGAGCGGTACGTGGTGGTGTGTAAGCCCATGAGCAACTTCCGCTTCGGGGAGAACCATGCCATCATGGGCGTTGCCTTCACCTGGGTCATGGCGCTGGCCTGCGCCGCACCCCCACTCGCCGGCTGGTCCAGGTACATCCCCGAGGGCCTGCAGTGCTCGTGTGGAATCGACTACTACACGCTCAAGCCGGAGGTCAACAACGAGTCTTTTGTCATCTACATGTTCGTGGTCCACTTCACCATCCCCATGATTATCATCTTTTTCTGCTATGGGCAGCTCGTCTTCACCGTCAAGGAGGCCGCTGCCCAGCAGCAGGAGTCAGCCACCACACAGAAGGCAGAGAAGGAGGTCACCCGCATGGTCATCATCATGGTCATCGCTTTCCTGATCTGCTGGGTGCCCTACGCCAGCGTG GC T TT T TA T AT ATTCACCCACCAGGGCTCCAACTTCGGTCCCATCTTCATGACCATCCCAGCGTTCTTTGCCAAGAGCGCCGCCATCTACAACCCTGTCATCTATATCATGATGAACAAGCAGTTCCGGAACTGCATGCTCACCACCATCTGCTGCGGCAAGAACCCACTGGGTGACGATGAGGCCTCTGCTACCGTGTCCAAGACGGAGACGAGCCAGGTGGCCCCGGCCTAA

Accordingly, compositions herein can be administered to a subject inneed of treatment. In some embodiments, the subject has or is suspectedof having one or more conditions, diseases, or disorders of the brainand/or eye. In some embodiments, the subject has or is suspected ofhaving one or more of the conditions, diseases, and disorders disclosedherein. In some embodiments, the subject has one or more endogenousmutant rho alleles (e.g., associated with or that cause a disease ordisorder of the eye or retina). In some embodiments, the subject has atleast one dominant mutant rho allele (e.g., that causes dominantretinitis pigmentosa). In some embodiments, the subject is a human. Insome embodiments, the subject is a non-human primate. Non-limitingexamples of non-human primate subjects include macaques (e.g.,cynomolgus or rhesus macaques), marmosets, tamarins, spider monkeys, owlmonkeys, vervet monkeys, squirrel monkeys, baboons, gorillas,chimpanzees, and orangutans. Other exemplary subjects includedomesticated animals such as dogs and cats; livestock such as horses,cattle, pigs, sheep, goats, and chickens; and other animals such asmice, rats, guinea pigs, and hamsters.

In some embodiments, the dose of rAAV particles administered to a cellor a subject may be on the order ranging from 10⁶ to 10¹⁴ particles/mLor 10³ to 10¹⁵ particles/mL, or any values therebetween for citherrange, such as for example, about 10⁶, 10⁷, 10⁸, 10⁹, 10¹⁰, 10¹¹, 10¹²,10¹³, or 10¹⁴ particles/mL. In one embodiment, rAAV particles of higherthan 10¹³ particles/mL are be administered. In some embodiments, thedose of rAAV particles administered to a subject may be on the orderranging from 10⁶ to 10¹⁴ vector genomes(vgs)/mL or 10³ to 10¹⁵ vgs/mL,or any values therebetween for either range, such as for example, about10⁶, 10⁷, 10⁸, 10⁹, 10¹⁰, 10¹¹, 10¹², 10¹³, or 10¹⁴ vgs/mL. In oneembodiment, rAAV particles of higher than 10¹³ vgs/mL are beadministered. The rAAV particles can be administered as a single dose,or divided into two or more administrations as may be required toachieve therapy of the particular disease or disorder being treated. Insome embodiments, 0.0001 mL to 10 mLs (e.g., 0.0001 mL, 0.001 mL. 0.01mL. 0.1 mL, 1 mL, 10 mLs) are delivered to a subject in a dose.

In some embodiments, rAAV viral titers range from 1×10¹⁰-5×10¹³ vg/ml,in some embodiments, rAAV viral titers can be 1×10¹⁰, 2.5×10¹⁰, 5×10¹⁰,1×10¹¹, 2.5×10¹¹, 5×10¹¹, 1×10¹², 2.5×10¹², 5×10¹², 1×10¹³, 2.5×10¹³, or5×10¹³ vg/mL. In some embodiments, viral titers are less than 1×10¹⁰vg/mL. In some embodiments, rAAV viral titers are greater than 1×10¹⁵vg/mL. In one embodiment, rAAV particles are greater than 5×10¹³ vgs/mL.In some embodiments, rAAV viral titers are administered via methodsfurther described herein (e.g., subretinally or intravitreally).

The rAAV particles can be administered as a single dose, or divided intotwo or more administrations as may be required to achieve therapy of theparticular disease or disorder being treated. In some embodiments, from1 to 500 microliters of a composition described in this application isadministered to one or both eyes of a subject. For example, in someembodiments, about 1, about 10, about 50, about 100, about 200, about300, about 400, or about 500 microliters can be administered to eacheye. However, it should be appreciated that smaller or larger volumescould be administered in some embodiments.

In some embodiments, the disclosure provides formulations of one or morerAAV-based compositions disclosed herein in pharmaceutically acceptablesolutions for administration to a cell or an animal, either alone or incombination with one or more other modalities of therapy, and inparticular, for therapy of human cells, tissues, and diseases affectingman.

If desired, rAAV particle or nucleic acid vectors may be administered incombination with other agents as well, such as, e.g., proteins orpolypeptides or various pharmaceutically-active agents, including one ormore systemic or topical administrations of therapeutic polypeptides,biologically active fragments, or variants thereof. In fact, there isvirtually no limit to other components that may also be included, giventhat the additional agents do not cause a significant adverse effectupon contact with the target cells or host tissues. The rAAV particlesmay thus be delivered along with various other agents as required in theparticular instance. Such compositions may be purified from host cellsor other biological sources, or alternatively may be chemicallysynthesized as described herein.

Formulation of pharmaceutically-acceptable excipients and carriersolutions is well-known to those of skill in the art, as is thedevelopment of suitable dosing and treatment regimens for using theparticular compositions described herein in a variety of treatmentregimens, including e.g., oral, parenteral, intravenous, intranasal,intra-articular, and intramuscular administration and formulation.

Typically, these formulations may contain at least about 0.1% of thetherapeutic agent (e.g., rAAV particle or host cell) or more, althoughthe percentage of the active ingredient(s) may, of course, be varied andmay conveniently be between about 1 or 2% and about 70% or 80% or moreof the weight or volume of the total formulation. Naturally, the amountof therapeutic agent(s) (e.g., rAAV particle) in eachtherapeutically-useful composition may be prepared in such a way that asuitable dosage will be obtained in any given unit dose of the compound.Factors such as solubility, bioavailability, biological half-life, routeof administration, product shelf life, as well as other pharmacologicalconsiderations will be contemplated by one skilled in the art ofpreparing such pharmaceutical formulations, and as such, a variety ofdosages and treatment regimens may be desirable.

In certain circumstances it will be desirable to deliver an rAAVparticle or host cell in suitably formulated pharmaceutical compositionsdisclosed herein either subcutaneously, intraocularly, intravitreally,parenterally, subcutaneously, intravenously, intracerebro-ventricularly,intramuscularly, intrathecally, orally, intraperitoneally, by oral ornasal inhalation, or by direct injection to one or more cells, tissues,or organs by direct injection.

The pharmaceutical forms of the rAAV particle or host cell compositionssuitable for injectable use include sterile aqueous solutions ordispersions. In some embodiments, the form is sterile and fluid to theextent that easy syringability exists. In some embodiments, the form isstable under the conditions of manufacture and storage and is preservedagainst the contaminating action of microorganisms, such as bacteria andfungi. The carrier can be a solvent or dispersion medium containing, forexample, water, saline, ethanol, polyol (e.g., glycerol, propyleneglycol, and liquid polyethylene glycol, and the like), suitable mixturesthereof, and/or vegetable oils. Proper fluidity may be maintained, forexample, by the use of a coating, such as lecithin, by the maintenanceof the required particle size in the case of dispersion and by the useof surfactants.

The term “carrier” refers to a diluent, adjuvant, excipient, or vehiclewith which the rAAV particle or host cell is administered. Suchpharmaceutical carriers can be sterile liquids, such as water and oils,including those of petroleum oil such as mineral oil, vegetable oil suchas peanut oil, soybean oil, and sesame oil, animal oil, or oil ofsynthetic origin. Saline solutions and aqueous dextrose and glycerolsolutions can also be employed as liquid carriers.

The compositions of the present disclosure can be administered to thesubject being treated by standard routes including, but not limited to,pulmonary, intranasal, oral, inhalation, parenteral such as intravenous,topical, transdermal, intradermal, transmucosal, intraperitoneal,intramuscular, intracapsular, intraorbital, intravitreal, intracardiac,transtracheal, subcutaneous, subeuticular, intraarticular, subcapsular,subarachnoid, intraspinal, epidural and intrasternal injection.

The compositions of the present disclosure can be delivered to the eyethrough a variety of routes. They may be delivered intraocularly, bytopical application to the eye or by intraocular injection into, forexample the vitreous (intravitreal injection) or subretinal (subretinalinjection) inter-photoreceptor space. In some embodiments, they aredelivered to rod photoreceptor cells. Alternatively, they may bedelivered locally by insertion or injection into the tissue surroundingthe eye. They may be delivered systemically through an oral route or bysubcutaneous, intravenous or intramuscular injection. Alternatively,they may be delivered by means of a catheter or by means of an implant,wherein such an implant is made of a porous, non-porous or gelatinousmaterial, including membranes such as silastic membranes or fibers,biodegradable polymers, or proteinaceous material. They can beadministered prior to the onset of the condition, to prevent itsoccurrence, for example, during surgery on the eye, or immediately afterthe onset of the pathological condition or during the occurrence of anacute or protracted condition.

For administration of an injectable aqueous solution, for example, thesolution may be suitably buffered, if necessary, and the liquid diluentfirst rendered isotonic with sufficient saline or glucose. Theseparticular aqueous solutions are especially suitable for intravenous,intramuscular, intravitreal, subcutaneous and intraperitonealadministration. In this connection, a sterile aqueous medium that can beemployed will be known to those of skill in the art in light of thepresent disclosure. For example, one dosage may be dissolved in 1 ml ofisotonic NaCl solution and either added to 1000 ml of hypodermoclysisfluid or injected at the proposed site of infusion, (see for example,“Remington's Pharmaceutical Sciences” 15th Edition, pages 1035-1038 and1570-1580). Some variation in dosage will necessarily occur depending onthe condition of the subject being treated. The person responsible foradministration will, in any event, determine the appropriate dose forthe individual subject. Moreover, for human administration, preparationsshould meet sterility, pyrogenicity, and the general safety and puritystandards as required by, e.g., FDA Office of Biologics standards.

Sterile injectable solutions are prepared by incorporating the rAAVparticles or host cells in the required amount in the appropriatesolvent with several of the other ingredients enumerated above, asrequired, followed by filtered sterilization. Generally, dispersions areprepared by incorporating the various sterilized active ingredients intoa sterile vehicle which contains the basic dispersion medium and therequired other ingredients from those enumerated above. In the case ofsterile powders for the preparation of sterile injectable solutions, thepreferred methods of preparation are vacuum-drying and freeze-dryingtechniques which yield a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof.

The amount of rAAV particle, nucleic acid vector, or host cellcompositions and time of administration of such compositions will bewithin the purview of the skilled artisan having benefit of the presentteachings. It is likely, however, that the administration oftherapeutically-effective amounts of the disclosed compositions may beachieved by a single administration, such as for example, a singleinjection of sufficient numbers of infectious particles to providetherapeutic benefit to the patient undergoing such treatment.Alternatively, in some circumstances, it may be desirable to providemultiple, or successive administrations of the rAAV particle or hostcell compositions, either over a relatively short, or a relativelyprolonged period of time, as may be determined by the medicalpractitioner overseeing the administration of such compositions.

In some embodiments, rod cells remain structurally intact and/or viableupon silencing of cellular rhodopsin gene expression. In someembodiments, rods cells in which cellular rhodopsin gene expression issilenced have shortened outer segments which would normally containrhodopsin. In some embodiments, the length of the outer segments can bemaintained or restored (e.g., partially or completely) using theexogenously added (hardened) rhodopsin gene, the expression of which isresistant to silencing using the compositions described in thisapplication.

The composition may include rAAV particles or host cells, either alone,or in combination with one or more additional active ingredients, whichmay be obtained from natural or recombinant sources or chemicallysynthesized. In some embodiments, rAAV particles are administered incombination, either in the same composition or administered as part ofthe same treatment regimen, with a proteasome inhibitor, such asBortezomib, or hydroxyurea.

To “treat” a disease as the term is used herein, means to reduce thefrequency or severity of at least one sign or symptom of a disease ordisorder experienced by a subject. The compositions described above aretypically administered to a subject in an effective amount, that is, anamount capable of producing a desirable result. The desirable resultwill depend upon the active agent being administered. For example, aneffective amount of a rAAV particle may be an amount of the particlethat is capable of transferring a heterologous nucleic acid to a hostorgan, tissue, or cell.

Toxicity and efficacy of the compositions utilized in methods of thedisclosure can be determined by standard pharmaceutical procedures,using either cells in culture or experimental animals to determine theLD50 (the dose lethal to 50% of the population). The dose ratio betweentoxicity and efficacy the therapeutic index and it can be expressed asthe ratio LD50/ED50. Those compositions that exhibit large therapeuticindices are preferred. While those that exhibit toxic side effects maybe used, care should be taken to design a delivery system that minimizesthe potential damage of such side effects. The dosage of compositions asdescribed herein lies generally within a range that includes an ED50with little or no toxicity. The dosage may vary within this rangedepending upon the dosage form employed and the route of administrationutilized.

Aspects of the disclosure relate to recombinant adeno-associated virus(rAAV) particles for delivery of one or more nucleic acid vectorscomprising a gene of interest into various tissues, organs, and/orcells. In some embodiments, the rAAV particles comprise an rAAV capsidprotein as described herein, e.g., comprising one or more amino acidsubstitutions. In some embodiments, the gene of interest encodes apolypeptide or protein of interest (e.g., a therapeutic polypeptide orprotein). In some embodiments, the gene of interest encodes an RNA ofinterest (e.g., a therapeutic mRNA, siRNA, shRNA, microRNA, antisenseRNA, tRNA, rRNA, or a ribozyme). In some embodiments, a gene of interestis a replacement gene (e.g., an eye-specific gene, a functional gene, afunctional RHO gene). In some embodiments, a gene of interest comprisesor encodes an RNA of interest (e.g., microRNA, siRNA, shRNA) and areplacement gene of interest (e.g., an eye-specific gene, a functionalgene, a functional RHO gene). In some embodiments, a functional RHO genecomprises an RHO gene comprising silent nucleotide substitutions thatrender it incapable of being degraded by an RNA of interest (e.g.,microRNA, siRNA, shRNA). In some embodiments, an RNA of interest and areplacement gene of interest are under the control of the same promoter.In some embodiments, an RNA of interest and a replacement gene ofinterest are under the control of separate promoters. Any suitablepromoters can be used, for example, but not limited to a viral promoter(e.g., a CMV or other viral promoter), a microbial (e.g., a yeast orbacterial), or a eukaryotic (e.g., a mammalian) promoter.

Recombinant AAV (rAAV) particles may comprise at a minimum (a) one ormore heterologous nucleic acid regions comprising a sequence encoding agene of interest (e.g., an RNA of interest and/or a replacement gene ofinterest) and (b) one or more regions comprising inverted terminalrepeat (ITR) sequences (e.g., wild-type ITR sequences or engineered ITRsequences) flanking the one or more heterologous nucleic acid regions.In some embodiments, the nucleic acid vector is between 4 kb and 5 kb insize (e.g., 4.2 to 4.7 kb in size). This nucleic acid vector may beencapsidated by a viral capsid, such as an AAV1, AAV2, AAV3, AAV4, orAAV5 capsid, which may comprise a modified capsid protein as describedherein. In some embodiments, the nucleic acid vector is circular. Insome embodiments, the nucleic acid vector is single-stranded. In someembodiments, the nucleic acid vector is double-stranded. In someembodiments, a double-stranded nucleic acid vector may be, for example,a self-complementary vector that contains a region of the nucleic acidvector that is complementary to another region of the nucleic acidvector, initiating the formation of the double-strandedness of thenucleic acid vector.

The rAAV particle may be of any AAV serotype, including any derivativeor pseudotype (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2/1, 2/5, 2/8, or2/9). As used herein, the serotype of an rAAV viral vector (e.g., anrAAV particle) refers to the serotype of the capsid proteins of therecombinant virus. In some embodiments, the rAAV particle is not AAV2.In some embodiments, the rAAV particle is AAV2. In some embodiments, therAAV particle is AAV6. In some embodiments, the rAAV particle is an AAV6serotype comprising an rAAV capsid protein as described herein.Non-limiting examples of derivatives and pseudotypes include rAAV2/1,rAAV2/5, rAAV2/8, rAAV2/9, AAV2-AAV3 hybrid, AAVrh.10, AAVhu.14,AAV3a/3b, AAVrh32.33, AAV-HSC15, AAV-HSC17, AAVhu.37, AAVrh.8, CHt-P6,AAV2.5. AAV6.2, AAV2i8, AAV-HSC15/17, AAVM41. AAV9.45,AAV6(Y445F/Y731F). AAV2.5T, AAV-HAEl/2, AAV clone 32/83. AAVShH10, AAV2(Y->F), AAV8 (Y733F), AAV2.15, AAV2.4, AAVM41, and AAVr3.45. Such AAVserotypes and derivatives/pseudotypes, and methods of producing suchderivatives/pseudotypes are known in the art (see, e.g., Mol Ther. 2012Apr.; 20(4):699-708. doi: 10.1038/mt.2011.287. Epub 2012 Jan. 24. TheAAV vector toolkit: poised at the clinical crossroads. Asokan A1,Schaffer D V, Samulski R J.). In some embodiments, the rAAV particle isa pseudotyped rAAV particle, which comprises (a) a nucleic acid vectorcomprising ITRs from one serotype (e.g., AAV2) and (b) a capsidcomprised of capsid proteins derived from another serotype (e.g., AAV1,AAV3, AAV4, AAV5, AAV6, AAV7. AAV8, AAV9, or AAV10). Methods forproducing and using pseudotyped rAAV vectors are known in the art (see.e.g., Duan et al., J. Virol., 75; 7662-7671, 2001; Halbert et al., J.Virol., 74:1524-1532, 2000; Zolotukhin et al., Methods, 28:158-167,2002; and Auricchio et al., Hum. Molec. Genet., 10:3075-3081, 2001).

Methods of producing rAAV particles and nucleic acid vectors are alsoknown in the art and commercially available (see, e.g., Zolotukhin etal. Production and purification of serotype 1, 2, and 5 recombinantadeno-associated viral vectors. Methods 28 (2002) 158-167; and U.S.Patent Publication Numbers US20070015238 and US20120322861, which areincorporated herein by reference; and plasmids and kits available fromATCC and Cell Biolabs, Inc.). For example, a plasmid containing thenucleic acid vector may be combined with one or more helper plasmids,e.g., that contain a rep gene (e.g., encoding Rep78, Rep68, Rep52 andRep40) and a cap gene (e.g., encoding VP1, VP2, and VP3, including amodified VP3 region as described herein), and transfected into aproducer cell line such that the rAAV particle can be packaged andsubsequently purified.

In some embodiments, the one or more helper plasmids include a firsthelper plasmid comprising a rep gene and a cap gene (e.g., encoding arAAV capsid protein as described herein) and a second helper plasmidcomprising a E1a gene, a E1b gene, a E4 gene, a E2a gene, and a VA gene.In some embodiments, the rep gene is a rep gene derived from AAV2 orAAV6 and the cap gene is derived from AAV2 or AAV6 and may includemodifications to the gene in order to produce the modified capsidprotein described herein. Helper plasmids, and methods of making suchplasmids, are known in the art and commercially available (see, e.g.,pDM, pDG, pDP1rs, pDP2rs, pDP3rs, pDP4rs, pDP5rs, pDP6rs,pDG(R484E/R585E), and pDP8.ape plasmids from PlasmidFactory, Bielefeld,Germany; other products and services available from Vector Biolabs,Philadelphia, Pa.; Cellbiolabs, San Diego, Calif.; Agilent Technologies,Santa Clara, Ca: and Addgene. Cambridge, Mass.; pxx6; Grimm et al.(1998), Novel Tools for Production and Purification of RecombinantAdenoassociated Virus Vectors, Human Gene Therapy, Vol. 9, 2745-2760;Kern, A. et al. (2003), Identification of a Heparin-Binding Motif onAdeno-Associated Virus Type 2 Capsids. Journal of Virology, Vol. 77,11072-11081.; Grimm et al. (2003), Helper Virus-Free. OpticallyControllable. and Two-Plasmid-Based Production of Adeno-associated VirusVectors of Serotypes 1 to 6, Molecular Therapy, Vol. 7, 839-850;Kronenberg et al. (2005). A Conformational Change in theAdeno-Associated Virus Type 2 Capsid Leads to the Exposure of Hidden VP1N Termini, Journal of Virology. Vol. 79, 5296-5303; and Moullier, P. andSnyder, R. O. (2008), International efforts for recombinantadeno-associated viral vector reference standards. Molecular Therapy,Vol. 16, 1185-1188).

An exemplary, non-limiting, rAAV particle production method is describednext. One or more helper plasmids are produced or obtained, whichcomprise rep and cap ORFs for the desired AAV serotype and theadenoviral VA. E2A (DBP), and E4 genes under the transcriptional controlof their native promoters. The cap ORF may also comprise one or moremodifications to produce a modified capsid protein as described herein.HEK293 cells (available from ATCC®) are transfected via CaPO4-mediatedtransfection, lipids or polymeric molecules such as Polyethylenimine(PEI) with the helper plasmid(s) and a plasmid containing a nucleic acidvector described herein. The HEK293 cells are then incubated for atleast 60 hours to allow for rAAV particle production. Alternatively, inanother example Sf9-based to producer stable cell lines are infectedwith a single recombinant baculovirus containing the nucleic acidvector. As a further alternative, in another example HEK293 or BHK celllines are infected with a HSV containing the nucleic acid vector andoptionally one or more helper HSVs containing rep and cap ORFs asdescribed herein and the adenoviral VA. E2A (DBP), and E4 genes underthe transcriptional control of their native promoters. The HEK293, BHK,or Sf9 cells are then incubated for at least 60 hours to allow for rAAVparticle production. The rAAV particles can then be purified using anymethod known the art or described herein, e.g., by iodixanol stepgradient, CsCl gradient, chromatography, or polyethylene glycol (PEG)precipitation.

The disclosure also contemplates host cells that comprise at least oneof the disclosed rAAV particles or nucleic acid vectors. Such host cellsinclude mammalian host cells, with human host cells being preferred, andmay be either isolated, in cell or tissue culture. In the case ofgenetically modified animal models (e.g., a mouse), the transformed hostcells may be comprised within the body of a non-human animal itself. Insome embodiments, the host cell is a cell of erythroid lineage, such asa CD36⁺ burst-forming units-erythroid (BFU-E) cell or a colony-formingunit-erythroid (CFUE-E) progenitor cell.

In some embodiments, compositions described herein (e.g., siRNA, shRNA,and/or replacement genes of interest) are formulated in a nanoparticle.In some embodiments, compositions described herein (e.g., siRNA, shRNA,and/or replacement genes of interest) are formulated in a lipidnanoparticle. In some embodiments, compositions described herein (e.g.,siRNA, shRNA, and/or replacement genes of interest) are formulated in alipid-polycation complex, referred to as a cationic lipid nanoparticle.The formation of the lipid nanoparticle may be accomplished by methodsknown in the art and/or as described in U.S. Pub. No. 20120178702,herein incorporated by reference in its entirety. As a non-limitingexample, the polycation may include a cationic peptide or a polypeptidesuch as, but not limited to, polylysine, polyornithine and/orpolyarginine and the cationic peptides described in International Pub.No. WO2012013326 or US Patent Pub. No. US20130142818; each of which isherein incorporated by reference in its entirety. In some embodiments,compositions described herein (e.g., siRNA, shRNA, and/or replacementgenes of interest) are formulated in a lipid nanoparticle that includesa non-cationic lipid such as, but not limited to, cholesterol ordioleoyl phosphatidylethanolamine (DOPE).

EXAMPLES Example 1: Identification of Short Interfering RNA (siRNA) thatKnockdown RHO

Using the short interfering RNA (siRNA) design principles described byKhvorova and colleagues^(4, 5), 14 siRNA were designed to cleave dogsiRNA specifically, 12 of which also target the human mRNA forrhodopsin. Before proceeding, the NCBI Blast utility(blast.ncbi.nlm.nih.gov/Blast.cgi) was used to screen positions 2through 19 of the siRNAs against the NCBI human RefSeq database. Two ofthe potential siRNA were excluded because they had close matches withother genes that might be expressed in the retina. RNA versions of 10 ofthe siRNAs were ordered from GE Healthcare Dharmacon together with anon-targeting siRNA to use as a control. These were tested in cellsexpressing human RHO fused to green fluorescent protein (GFP, exemplaryplasmid map depicted in FIG. 11), and reduction in green fluorescentcells was measured by fluorescence activated cell sorting (FACS). Therationale was that cleavage of RHO mRNA would reduce the production ofGFP. While all of the siRNAs were designed based on current designprinciples for siRNAs, only 3 of 10 that were tested led to reduction of30% or more (FIG. 1A-C).

To confirm that these siRNAs would be effective as small hairpin RNAsexpressed from an RNA polymerase III promoter and delivered by AAV, theDNA sequences for shRNAs were cloned expressing three of the siRNAs(FIG. 2). Interestingly, the relative knockdown of RHO using siRNA didnot exactly predict relative suppression of RHO using shRNA, since siRNA131 (SEQ ID NO: 1) was the most effective siRNA, but the least effectiveof the shRNAs that were tested. Simple transfection of siRNAs as RNA maynot exactly predict the effectiveness of shRNA designed to produce thesame siRNAs by transcription and processing.

To confirm that the shRNAs would be effective in cleaving both wild type(normal) and mutant RHO, the same three shRNA cloned in an AAV vectorwere tested for their ability to digest wild type and two differentmutant RHO mRNAs using quantitative reverse transcription PCR (qRT-PCR)as an assay (FIG. 3).

Table 5 lists RNA sequences corresponding to shRNA sequences identifiedas capable of cleaving RHO, including the sense strand, loop, antisensestrand, and overhang. Each sequence is depicted with two alternativeloop sequences that are bolded and underlined for emphasis, withoverhangs italicized and underlined for emphasis.

TABLE 5 Small hairpin RNA (shRNA) SEQ RNA sequence IDSense Strand - Loop - NO: Name Antisense Strand - Overhang) 20 RHO131-9CUGCCUACAUGUUUCUGCU UCAAGAG AGCAGAA ACAUGUAGGCAG UU 21 RHO131-10CUGCCUACAUGUUUCUGCU UGUGCUU AGCAGAA ACAUGUAGGCAG UU 22 RHO134-9CCUACAUGUUUCUGCUGAU UCAAGAG AUCAGCA GAAACAUGUAGG UU 23 RHO134-10CCUACAUGUUUCUGCUGAU UGUGCUU AUCAGCA GAAACAUGUAGG UU 24 RHO765-9GCAUGGUCAUCAUCAUGGU UCAAGAG ACCAUGA UGAUGACCAUGC UU 25 RHO765-10GCAUGGUCAUCAUCAUGGU UGUGCUU ACCAUGA UGAUGACCAUGC UU 26 RHO820-9GUGGCAUUCUACAUCUUCA UCAAGAG UGAAGAU GUAGAAUGCCAC UU 27 RHO820-10GUGGCAUUCUACAUCUUCA UGUGCUU UGAAGAU GUAGAAUGCCAC UU

siRNAs can also be delivered as artificial microRNAs⁷ of a structurelike that in FIG. 4. The exemplary microRNA of FIG. 4 comprises sense(100) and antisense (101) strands of RHO131 (SEQ ID NOs: 1 and 2,respectively). The advantage of this mode of expression is thatproduction of the siRNA can be made cell type specific through the useof a specific promoter sequence. In this case the proximal promoter ofthe human rhodopsin gene or the human rhodopsin kinase promoter would beused to restrict expression to photoreceptor cells.

Example 2: Analysis of RHO KD in RHO^(+/+) Dogs

Dog 2190 (red1 carrier) received subretinal injections ofAAV2/5-sc-H1-shRNA-Rho131 at the concentrations listed in Table 6. Thedog was terminated 8 weeks post injection. Several 3 mm neuroretinalbiopsy punches were collected from each eye from both bleb and non-blebregions.

TABLE 6 Dog 2190 Age at Dog Genotype Sex DOB injection Right Eye (OD)Left Eye (OS) 2190 rcd1 M Aug. 11, 2014 1 year AAV2/5-sc-H1-AAV2/5-sc-H1- carrier shRNA-Rho131 shRNA-Rho131 Ω4063 Ω4063 5E + 12vg/ml 1E + 12 vg/ml 150 μl SR 150 μl SR

The non-limiting examples of AAV2/5-sc-H1-shRNA constructs describedherein can also be referred to as AAV2/5-sc-MOP500 rGFP-shRNAconstructs. The AAV2/5 indicates that the nucleic acid encoding theshRNA is flanked by AAV2 ITRs and provided in an rAAV particlecomprising AAV5 capsid proteins. In some embodiments, any interferingRNA described herein and any recombinant RHO gene described herein canbe provided on the same AAV nucleic acid (e.g., flanked by AAV2 ITRs) inan rAAV particle (e.g., comprising AAV5 capsid proteins). In someembodiments, any interfering RNA described herein and any recombinantRHO gene described herein can be provided on different AAV nucleic acids(e.g., each flanked by AAV2 ITRs, or each flanked by ITRs from differentAAV serotypes) encapsidated in different rAAV particles (e.g., eachcomprising AAV5 capsid proteins, or each having capsid proteins fromdifferent AAV serotypes).

Western Blot Analysis:

Two biopsy punches from each eye, representing either bleb or non-blebregions, were incubated in 50 μl of Lewin buffer solution A (withprotease inhibitors) for 15 minutes on ice. The samples were sonicatedat 40% amplitude, 15 secON/10 secOFF ×8 pulses. Samples were thencentrifuged and the pellet discarded. Protein concentration in thesupernatant was measured by Bradford method. 1 μg of total protein wasimmunoblotted to visualize rhodopsin (antibody used: Millipore MAB5356,diluted 1:1000 in ODYSSEY® blocking buffer), and anti-histone antibody(Abcam ab1791, diluted 1:3000) was used as a loading control (FIG. 5A)and to normalize the signals (FIG. 5B). Comparison between RHO proteinamounts between bleb and non-blcb regions were not consistent with theexperimental design (FIG. 5C).

Absolute Quantitation of Canine Rhodopsin RNA in Canine Retina:

In order to determine the absolute amounts of rhodopsin RNA present inthe retina after ribozyme-treatment, absolute quantitation was performedusing Q-PCR Standard Curve method. Dilution series of known quantitiesof canine RHO cDNA was used to construct a standard curve. Total amountof canine RHO RNA in each sample was calculated based on this standardcurve (FIG. 6A).

Partial knockdown of canine RHO is seen with AAV2/5-sc-H1-shRNA-Rho131.At the highest concentration used, protein levels are decreased by 37%,whereas RNA is decreased by nearly 50% (FIG. 6B).

Example 3: Further Analysis of RHO KD in RHO^(+/+) Dogs

Dog 2194 (red1 carrier) received subretinal injections ofAAV2/5-sc-H1-shRNA-Rho820 at the concentrations listed in Table 7. Thedog was terminated 8 weeks post injection. Several 3 mm neuroretinalbiopsy punches were collected from each eye from both bleb and non-blebregions.

TABLE 7 Dog 2194 Age at Dog Genotype Sex DOB injection Right Eye (OD)Left Eye (OS) 2194 rcd1 F Aug. 11, 2014 1 year AAV2/5-sc-H1-AAV2/5-sc-H1- carrier shRNA-Rho820 shRNA-Rho820 Ω4064 Ω4064 5E + 12vg/ml 1E + 12 vg/ml 150 μl SR Small blcb 50 μl SR 50 μl intravitr 250 μlintravitr

Western Blot Analysis:

Two biopsy punches from each eye, representing either bleb or non-blebregions, were incubated in 50 μl of Lewin buffer solution A (withprotease inhibitors) for 15 minutes on ice. The samples were sonicatedat 40% amplitude, 15 secON/10 secOFF ×8 pulses. Samples were thencentrifuged and the pellet discarded. Protein concentration in thesupernatant was measured by Bradford method. 1 μg of total protein wasimmunoblotted to visualize rhodopsin (antibody used: Millipore MAB5356,diluted 1:1000 in ODYSSEY® blocking buffer). Anti-histone antibody(Abeam ab1791, diluted 1:3000) was used as a loading control (FIG. 7A)and to normalize the signals (FIG. 7B). Comparison between RHO proteinamounts between bleb and non-bleb regions were not consistent with theexperimental design (FIG. 7C).

Absolute Quantitation of Canine Rhodopsin RNA in Canine Retina:

In order to determine the absolute amounts of rhodopsin RNA present inthe retina after ribozyme-treatment, absolute quantitation was performedusing Q-PCR Standard Curve method. Dilution series of known quantitiesof canine RHO cDNA was used to construct a standard curve. Total amountof canine RHO RNA in each sample was calculated based on this standardcurve (FIG. 8A).

Complete knockdown of canine RHO RNA and protein is seen withAAV2/5-sc-H1-shRNA-Rho820 even at the lower dose of 1×10¹² vg/ml (FIG.8B).

Example 4: Hardened mRNA Sequences for Replacement Gene

In some embodiments, an mRNA for a replacement gene (e.g., replacementRHO) can be modified at one or more positions to “harden” it (i.e., tomake it resistant to degradation by siRNA). In some embodiments, one ormore silent nucleotide substitutions can be included in the replacementgene relative to the siRNA that is provided to knockdown the endogenousgene (e.g., RHO gene). FIGS. 9 and 10 provide non-limiting examples ofnucleotide substitutions that can be introduced into the replacement RHOmRNA. It should be appreciated that a replacement RHO gene can includeone or more of these substitutions.

FIG. 9 depicts a representation of base pairing that occurs between eachshRNA and the target sequence of endogenous human or hardened RHO mRNA.All shRNAs base-pair perfectly with the target sequence of RHO mRNA ofdog. White box: mismatch between shRNA and endogenous dog as well ashardened RHO mRNA. Dark gray box: a weak wobble base pairing that occursin RNA between guanosine and uracil. Light gray box: mismatch betweenshRNA and hardened RHO mRNA only.

FIG. 10 depicts a representation of base pairing that occurs betweenshRNA134 and the target sequence of endogenous human or hardened RHO131mRNA. The proximity of the target sequences of shRNAs 131 and 134enables the same hardened RHO131 to be employed. Dark gray box: a weakwobble base pairing that occurs in RNA between guanosine and uracil.Light gray box: mismatch between shRNA and hardened RHO mRNA only.

Example 5: Encoding siRNA and Replacement Genes

In some embodiments, it may be desirable to provide siRNA encoded in aDNA vector. FIGS. 12A-B depict non-limiting examples of siRNA (e.g.,shRNA) encoded in a DNA vector. In some embodiments, as further depictedin the exemplary plasmid maps shown in FIG. 12A-B, the DNA vector canfurther encode inverted terminal repeat (ITR) sequences flanking thesiRNA (e.g., shRNA). In some embodiments, a DNA vector encoding siRNAflanked by ITR sequences can be used in the production of recombinantAAV particles comprising the siRNA.

In some embodiments, it may be desirable to provide a replacement RHOmRNA encoded in a DNA vector. FIG. 12C depicts a non-limiting example ofa replacement RHO mRNA (e.g., Human RHO) encoded in a DNA vector. Insome embodiments, as further depicted in the exemplary plasmid map shownin FIG. 12C, the DNA vector can further encode ITR sequences flankingthe replacement RHO mRNA (e.g., Human RHO). In some embodiments, a DNAvector encoding replacement RHO mRNA flanked by ITR sequences can beused in the production of recombinant AAV particles comprising the Humanrho. In some embodiments, a similar DNA vector may be provided thatincludes both the replacement rho gene and one or more sequencesencoding one or more interfering RNAs flanked by ITR sequences. In someembodiments, the interfering RNAs and/or replacement rho genes areoperatively coupled to a promoter (e.g., an RNA polymerase III promoter,or H1 RNA polymerase III promoter, or other promoter as described inthis application). The interfering RNAs and/or replacement rho genesrepresented in FIGS. 12A-C are under the control of an H1 RNA polymeraseIII promoter. The constructs of FIGS. 12A-C also include a MOP500-rGFP(a −385/+86 portion of the mouse rod opsin promoter (MOP500) upstream ofthe reversed sequence of GFP (rGFP) that is therefore not expressed) andcan be referred to as H1 constructs or MOP500 constructs. However, theMOP500 (e.g., MOP500-rGFP) portion is not required. Accordingly, aplasmid or rAAV nucleic acid can encode an interfering RNA and/or amodified rho gene as described herein, each under the control of thesame or a different promoter (e.g., an H1 promoter) without a mouseopsin promoter and/or without any GFP coding sequence (in eitherorientation).

Example 6: Analysis of RHO KD with shRNA820 in WT RHO^(+/+) Dogs

Example 6 includes the identification of viral titers of AAV2/5 carryingthe shRNA820 knockdown reagent that efficiently silence rhodopsinexpression after subretinal injection in WT dogs, evidence by in vivoretinal imaging in WT dogs of the preservation of the layer (ONL) thatcontains the photoreceptors, but reduction of the layers that containrhodopsin following subretinal injection with AAV2/5-sc-H1-shRNA820,identification of viral titers of AAV2/5 carrying the shRNA820 knockdownreagent that efficiently silence rhodopsin expression after subretinalinjection in the mutant RHO^(T4R/+) dog, a naturally-occurring model ofRHO-ADRP, identification of viral titers of AAV2/5-sc-H1-shRNA820 thatconfer protection to photoreceptors from light-induced retinaldegeneration in the mutant RHO^(T4R/+) dogs, evidence that efficientknockdown of rhodopsin expression leads to a loss of outer segments inrods. Since preservation of outer segments is critical tophototransduction (the mechanism by which rods convert light into anelectrical signal), an optimal therapy for RHO-ADRP should reduce nativeRHO but preserve outer segment structure. These results demonstrate thata knockdown approach is not sufficient and argue for the use of acombined knockdown and replacement strategy.

Five WT RHO^(+/+) dogs received subretinal injections ofAAV2/5-sc-H1-shRNA-Rho820 in both eyes at viral concentrations rangingfrom 1×10¹¹ to 5×10¹² vg/ml) as indicated in Table 8 below.

TABLE 8 RHO KD with shRNA820 in WT RHO^(+/+) dogs Age at Dog GenotypeSex DOB injection Right Eye (OD) Left Eye (OS) 2194 rcd1 carrier F Aug.11, 1 year AAV2/5-sc-H1- AAV2/5-sc-H1- 2014 shRNA-Rho820 shRNA-Rho820Ω4064 Ω4064 5E + 12 vg/ml 1E + 12 vg/ml 150 ul SR Small bleb 50 ul SRBR442 RPE65 F Dec. 15, 1 Y + AAV2/5-sc-H1- AAV2/5-sc-H1- carrier 2013 11M shRNA820 shRNA820 Ω4064 Ω4064 1E + 12 vg/ml 1E + 12 vg/ml 150 ul SR150 ul SR GSR2 CNGB3 M Aug. 19, 64 wks AAV2/5-sc-H1- AAV2/5-sc-H1-carrier 2014 shRNA820 shRNA820 rcd1 carrier Ω4064 Ω4064 5E + 11 vg/ml5E + 11 vg/ml 150 ul SR 110 ul SR P1474 prcd carrier M Sep. 30, 392weeks/ AAV2/5-sc-H1- AAV2/5-sc-H1- 2008 7 y shRNA820 shRNA820 Ω4064Ω4064 2.5E + 11 vg/ml 2.5E + 11 vg/ml 150 ul SR 150 ul SR N282 WT M Sep.6, 6 yrs + AAV2/5-sc-H1- AAV2/5-sc-H1- 2009 2 M shRNA820 shRNA820 Ω4064Ω4064 1E + 11 vg/ml 1E + 11 vg/ml 150 ul SR 160 ul SR

At 6-8 weeks post injection in vivo retinal imaging (cSLO/OCT) wasperformed and dogs were then terminated. Several 3 mm neuroretinalbiopsy punches were collected from both eyes (dog 2194) or from the OSeye only (other dogs) in both bleb/treated and non-bleb/untreatedregions to measure the level of expression of canine rhodopsin bywestern blot and RHO RNA by qPCR analysis. The OD eye was fixed,embedded in optimal cutting temperature media and processed forhistology and immunohistochemistry staining.

Western Blot Analysis:

Up to three pairs of biopsy punches representing either bleb or non-blebregions, were incubated in 50 ul of Lewin buffer solution A (containingprotease inhibitors) for 15 min on ice. The samples were sonicated at40% amplitude. 15 secON/10 secOFF ×8 pulses. Samples were thencentrifuged and the pellet discarded. Protein concentration in thesupernatant was measured by Bradford method. Samples were stored at −20°C. 1 ug of total protein was loaded on gel for visualizing rhodopsin(Antibody used: Millipore MAB5356, diluted 1:1000 in Odyssey blockingbuffer). Anti-histone H3 antibody (Abcam ab1791, diluted 1:3000) wasused as a loading control and to normalize the signals.

Absolute Quantitation of Canine Rhodopsin RNA in Canine Retina:

In order to determine the absolute amounts of Rhodopsin RNA present inthe retina after shRNA820-treatment, absolute quantitation was performedusing Q-PCR Standard Curve method. Dilution series of known quantitiesof canine RHO cDNA was used to construct a standard curve. 0.1 nanogramof total cDNA was used for quantitation. Total amount of canine RHO RNAin each sample was calculated based on this standard curve.

Evaluation by In Vivo Retinal Imaging of Retinal Integrity in Eyes of WTRHO^(+/+) Dogs Injected with Different Viral Titers ofAAV2/5-Sc-H1-shRNA820.

In vivo retinal imaging by cSLO/OCT was used to assess the retinalintegrity of the ONL 6 to 8 weeks post subretinal injection of differenttiters of AAV2/5-sc-H1-shRNA820. Topographical maps of ONL thicknessshowed a preservation of this layer at all titers. Segmentation of theexternal limiting membrane (ELM), inner segments (IS), and outersegments (OS) revealed a reduction in signal intensity in the regioncorresponding to the bleb area in eyes injected with 1×10¹² and 5×10¹²vg/ml titers. These results suggest a shortening of the photoreceptor OSand IS as a results of RHO silencing and may be used to assess theefficacy of RHO KD in vivo. FIGS. 13A-13E show RNA and protein analysisof rhodopsin knockdown with different viral titers ofAAV2/5-sc-H1-shRNA820 injected subretinally in WT RHO^(+/+) dogs. FIG.13A shows retinal maps showing position of biopsy punches used forwestern blot analysis and RNA quantitation. Paired dark gray, gray anddotted circles indicate the position of biopsy punches in thebleb/treated and non-bleb/untreated regions for each replication ofwestern blot, whereas the black circles indicate the positions of biopsypunches for RNA quantitation. FIG. 13B shows a bar graph showingremaining canine Rhodopsin RNA in the treated area as a percentage oflevels measured in the untreated area of the same retina. FIG. 13C showsimmunoblot showing the amount of Rhodopsin in biopsy punches taken fromtreated (Tx) and untreated (UnTx) areas of canine retina. Histone H3 wasused for normalization. Bar graphs show remaining canine Rhodopsinprotein as a percentage of levels measured in the untreated area of thesame retina. FIGS. 13D-13E show tables showing numerical values fromeach experiment (reported as a percentage of RNA or protein remaining,and alternatively as a percent knockdown of RNA or protein,respectively).

FIGS. 14A-D show the assessment of ONL and ELM/IS/OS integrity followingsubretinal injection of different titers of AAV2/5-sc-H1-shRNA820 in WTdogs. FIG. 14A shows ONL thickness maps; FIG. 14B shows ELM/IS/OS mapsof normalized intensity; FIG. 14C shows ONL thickness values; and FIG.14D shows values of normalized intensity of the ELM/IS/OS layers. Theseresults suggest a shortening of the photoreceptor OS and IS as a resultsof RHO silencing and may be used to assess the efficacy of RHO KD invivo.

Complete knockdown of canine RHO RNA and protein was seen in WT dogswith AAV2/5-sc-H1-shRNA820 injected subretinally at viral titers as lowas 1×10¹² vg/ml. No reduction in ONL thickness was seen even with thehighest viral concentration suggesting that knockdown of rhodopsin doesnot induce photoreceptor cell death. A decrease in OCT reflectivity ofthe ELM/IS/OS layers is seen in the treated/bleb region of eyes injectedwith high viral titers that induce 100% KD of rhodopsin. Thisobservation is compatible with a thinning of these layers and may beused as an in vivo outcome measure of KD efficiency.

Example 7: Analysis of RHO KD with shRNA820 in RHO^(T4R/+) Mutant Dogs

Four RHO^(T4R/+) dogs received subretinal injections ofAAV2/5-sc-H1-shRNA-Rho820 in both eyes at viral concentrations indicatedin Table 9 below.

TABLE 9 RHO KD with shRNA820 in RHO^(T4R/+) mutant dogs Age at DogGenotype Sex DOB injection Right Eye (OD) Left Eye (OS) EM409 T4R/+ FFeb. 10, 2015 40 wks AAV2/5-sc-H1- AAV2/5-sc-H1- shRNA820 shRNA820 Ω4064Ω4064 1E + 12 vg/ml 1E + 12 vg/ml 150 ul SR 150 ul SR EM411 T4R/+ F Feb.10, 2015 40 wks AAV2/5-sc-H1- AAV2/5-sc-H1- shRNA820 shRNA820 Ω4064Ω4064 5E + 11 vg/ml 5E + 11 vg/ml 160 ul SR 150 ul SR EM413 T4R/+ F Feb.10, 2015 57 weeks AAV2/5-sc-H1- AAV2/5-sc-H1- shRNA820 shRNA820 Ω4064Ω4064 2.5E + 11 vg/ml 2.5E + 11 vg/ml 150 ul SR 150 ul SR EM412 T4R/+ FFeb. 10, 2015 40 wks AAV2/5-sc-H1- AAV2/5-sc-H1- shRNA820 shRNA820 Ω4064Ω4064 1E + 11 vg/ml 1E + 11 vg/ml 150 ul SR 150 ul SR

cSLO/OCT was performed at 8 weeks post injection and light exposure (1min at 1 mW/cm²) was performed on OS eye in all dogs to triggerlight-induced retinal degeneration. cSLO/OCT was performed again on alldogs 2 weeks post light exposure to assess any rescue effect conferredby the treatment. Dogs were terminated and several 3 mm neuroretinalbiopsy punches were collected from OD eye from both bleb/treated andnon-bleb/untreated regions to measure the level of expression of canineRhodopsin by western blot and RHO RNA by qPCR analysis. The OS eye wasfixed, embedded in optimal cutting temperature media and processed forhistology and immunohistochemistry staining.

Western Blot Analysis:

Three pairs of biopsy punches from each OS eye, representing eitherbleb/treated or non-bleb/untreated retinal regions, were incubated in 50ul of Lewin buffer solution A (containing protease inhibitors) for 15min on ice. The samples were sonicated at 40% amplitude. 15 secON/10secOFF ×8 pulses. Samples were then centrifuged and the pelletdiscarded. Protein concentration in the supernatant was measured byBradford method. Samples were stored at −20° C. 1 ug of total proteinwas loaded on gel for visualizing Rhodopsin (Antibody used: MilliporeMAB5356, diluted 1:1000 in Odyssey blocking buffer). Anti-histone H3antibody (Abcam ab1791, diluted 1:3000) was used as a loading controland to normalize the signals.

Absolute Quantitation of Canine Rhodopsin RNA in Canine Retina:

In order to determine the absolute amounts of Rhodopsin RNA present inthe retina after shRNA820-treatment, absolute quantitation was performedusing Q-PCR Standard Curve method. Dilution series of known quantitiesof canine RHO cDNA was used to construct a standard curve. 0.1 nanogramof total cDNA was used for quantitation. Total amount of canine RHO RNAin each sample was calculated based on this standard curve.

Evaluation by In Vivo Retinal Imaging of Photoreceptor Rescue fromLight-Induced Damage in Eyes of Mutant RHO^(T4R/+) Dogs Injected withDifferent Viral Titers of AAV2/5-shRNA820.

Eyes from mutant RHO^(T4R/+) dogs that were subretinally injected withviral titers ranging from 1×10¹² down to 1×10¹¹ vg/ml were examined bycSLO/OCT imaging 8 weeks post injection (before light exposure). ONLthickness in the bleb/treated area was preserved suggesting thatshRNA820 did not cause any loss of photoreceptors during that period. A1 min exposure to white light at an intensity (corneal irradiance of 1mW/cm²) previously shown to cause acute retinal degeneration in RHO T4Rmutant but not in WT dogs was used to assess the level of protectionconferred by the AAV2/5-sc-H1-shRNA820 in the treated/bleb area. Thesurrounding non bleb/untreated regions were used as an internal controlfor each eye. Two weeks post light-exposure retinas were re-imaged, andshowed good preservation of ONL thickness in the bleb/treated area ofeyes injected with 1×10¹² and 5×10¹¹ vg/ml titers. Very mild rescue wasseen at 2.5×10¹¹ vg/ml and none with 1×10¹¹ vg/ml titers.

FIGS. 15A-15E show RNA and protein analysis of rhodopsin knockdown withdifferent viral titers of AAV2/5-sc-H1-shRNA820 injected subretinally inmutant RHO^(T4R/+) dogs. FIG. 15A shows retinal maps showing position ofbiopsy punches used for western blot analysis and RNA quantitation.Paired dark gray, gray and dotted circles indicate the position ofbiopsy punches in the bleb and non-bleb region for each replication ofwestern blot, whereas the black circles indicate the position of biopsypunches for RNA quantitation. FIG. 15B is a bar graph showing the amountof remaining canine Rhodopsin RNA as a percentage of levels measured inthe untreated area of the same retina. FIG. 15C is an immunoblot showingthe amount of canine Rhodopsin in biopsy punches taken from treated (Tx)and untreated (UnTx) areas of canine retina. Histone H3 was used fornormalization. Bar graphs show the amount of remaining canine Rhodopsinprotein as a percentage of levels measured in the untreated area of thesame retina. FIGS. 15D-15E are tables showing numerical values from eachexperiment (reported as a percentage of RNA or protein remaining, andalternatively as a percent knockdown of RNA or protein, respectively).

FIGS. 16A-16D show OCT B scans encompassing the treated (with differentviral titers of AAV2/5-sc-H1-shRNA820) and untreated retinal areas ofRHO^(T4R/+) dogs 2 weeks following exposure to a brief dose of lightthat causes acute retinal degeneration in mutant RHO^(T4R/+) dogs. (FIG.16A) OCT scan of a dog treated with 1×10¹² vg/ml. (FIG. 16B) OCT scan ofa dog treated with 5×10¹¹ vg/ml. (FIG. 16C) OCT scan of a dog treatedwith 2.5×10¹¹ vg/ml. (FIG. 16D) OCT scan of a dog treated with 1×10¹¹vg/ml. FIGS. 17A-17B show topographic map ONL thickness from aRHO^(T4R/+) treated with AAV2/5-sc-shRNA820 showing protection fromlight-induced retinal degeneration. (FIG. 17A) ONL thickness map of anuntreated WT control dog (left panel), and ONL thickness map of EM411-OStreated with AAV2/5-sc-shRNA820 at 5E+11 vg/ml and showing preserved ONLthickness in the treated/bleb region weeks after light-induced damage.Black and white curve shows the limits of the bleb as seen immediatelyafter the subretinal injection. Panels below show OCT B scans with ONLcolored in darker gray (middle band) for visualization purposes. (FIG.17B) Loci outside and inside the bleb were selected for ONL thicknessmeasurements.

Complete knockdown of canine RHO RNA and protein (by western blot) wasseen with AAV2/5-shRNA-Rho820 at a viral titer of 1×10¹² and 5×10¹¹vg/ml. Complete rescue of the outer nuclear layer (ONL) which containsthe cells bodies of the photoreceptors was achieved withAAV2/5-shRNA-Rho820 at a viral titer of 1×10¹² and 5×10¹¹ vg/ml.

Evaluation by Histology and Immunohistochemistry of PhotoreceptorProtection from Light-Induced Damage in Eyes of Mutant RHO^(T4R/+) DogsInjected with Different Viral Titers of AAV2/5-sc-H1-shRNA820.

Eyes from the same mutant RHO^(T4R/+) dogs listed in the above Tablethat were subretinally-injected with viral titers ranging from 1×10¹²down to 1×10¹¹ vg/ml and subsequently light exposed (at 8 weeks postinjection) to 1 min duration of white light at an intensity (cornealirradiance of 1 mW/cm²) were examined. This dose of light was previouslyshown to cause acute retinal degeneration in RHO T4R mutant but not inWT dogs. Histology and immunohistochemistry were used to assess thelevel of protection conferred by the AAV2/5-sc-H1-shRNA820 in thetreated/bleb area. The surrounding non bleb/untreated regions were usedas an internal control for each eye. Antibodies directed againstrhodopsin (RHO), and human cone arrestin (hCA) were used to assess theintegrity of rod outer segments and cone morphology. FIG. 18 showshistology (H&E stained) and immunohistochemistry (Rhodopsin was stainedin green and appears as the lighter staining in the lower panels of FIG.18; human cone arrestin was stained in red and appears as the graystaining in the lower panels of FIG. 18) in the treated (Tx) andUntreated (UnTx) areas of mutant RHO^(T4R/+) retinas injectedsubretinally with different viral titers AAV2/5-sc-H1-shRNA820. Twoweeks post light-exposure good preservation of ONL thickness in thebleb/treated area of eyes injected with 1×10¹² and 5×10¹¹ vg/ml titerswas seen, while ONL thickness was slightly reduced at 2.5×10¹¹ vg/ml,and no protection was observed with 1×10¹¹ vg/ml titers. Consistent withthe very efficient knockdown of rhodopsin expression at 1×10¹² and5×10¹¹ vg/ml titers, and reduction in the length of rod OS was seen onH&E sections, combined with a reduction in rhodopsin expression.

Complete knockdown of canine RHO RNA and protein (by western blot) isseen with AAV2/5-sc-H1-shRNA820 at a viral titer of 1×10¹² and 5×10¹¹vg/ml. Complete protection of the outer nuclear layer (ONL) whichcontains the cells bodies of the photoreceptors is achieved withAAV2/5-sc-H1-shRNA820 at a viral titer of 1×10¹² and 5×10¹¹ vg/ml. Lossof outer segment structure in rods as a result of efficient RHOknockdown argues for the need of a combined KD and replacement strategyto allow treated rods to retain outer segments and remain functional.

Example 8

This Example provides data supporting gene therapy using RHO-ADRP. Itincludes testing in mutant RHO^(T4R/+) dog an AAV2/5 vector construct(AAV2/5-sc-HOP-RHO820-H1-shRNA820) that combines both the shRNA820knockdown reagent and the replacement reagent RHO820 (=hardened humanRHO mRNA), identification of viral titers ofAAV2/5-sc-HOP-RHO820-H1-shRNA820 that result in efficient knockdown ofendogenous canine RHO, and efficient expression of the replacementhardened human RHO (RHO820), evidence thatAAV2/5-sc-HOP-RHO820-H1-shRNA820 confers protection to photoreceptorsfrom light-induced retinal degeneration in the mutant RHO^(T4R/+) dogs,and evidence that preservation of rod outer segments is achieved inretinal areas treated with AAV2/5-sc-HOP-RHO820-H1-shRNA820.

Analysis of RHO KD & Replacement with shRNA820 and RHO820 in RHO^(T4R/+)Mutant Dogs:

Two RHO^(T4R/+) dogs received subretinal injections ofAAV2/5-sc-HOP-RHO820-H1-shRNA820 in both eyes at viral concentrationsindicated in the table below (Table 10).

TABLE 10 Age at Dog Genotype Sex DOB injection Right Eye (OD) Left Eye(OS) EM424 T4R/+ M Apr. 29, 2016 27 weeks AAV2/5-sc-HOP- AAV2/5-sc-HOP-RHO820-H1-shRNA820 RHO820-H1-shRNA820 P4337 P4337 5E + 11 vg/ml 5E + 11vg/ml 150 ul SR 150 ul SR EM425 T4R/+ M Apr. 29, 2016 27 weeksAAV2/5-sc-HOP- AAV2/5-sc-HOP- RHO820-H1- RHO820-H1- shRNA820 shRNA820P4337 P4337 5E + 11 vg/ml 5E + 11 vg/ml 150 ul SR 150 ul SR HOP: humanopsinpromoter; H1: H1 RNA polymerase III promoter

In vivo retinal imaging (cSLO/OCT) was performed at 11 weeks postinjection and light exposure (1 min at 1 mW/cm²) was performed on OS eyein both dogs to trigger light-induced retinal degeneration. cSLO/OCT wasperformed again on all dogs 2 weeks post light exposure to assess anyrescue effect conferred by the treatment. Dogs were terminated andseveral 3 mm neuroretinal biopsy punches were collected from OD eye fromboth bleb/treated and non-bleb/untreated regions to measure the level ofexpression of Rhodopsin by western blot and canine and human RHO RNA byqPCR analysis. The OS eye was fixed, embedded in optimal cuttingtemperature media and processed for histology and immunohistochemistrystaining.

Western Blot Analysis:

Three pairs of biopsy punches from each OD eye, representing eitherbleb/treated or non-bleb/Untreated retinal regions, were incubated in 50ul of Lewin buffer solution A (containing protease inhibitors) for 15min on ice. The samples were sonicated at 40% amplitude, 15 sec ON/10sec OFF ×8 pulses. Samples were then centrifuged and the pelletdiscarded. Protein concentration in the supernatant was measured byBradford method. Samples were stored at −20° C. 1 ug of total proteinwas loaded on gel for visualizing Rhodopsin (Antibody used: MilliporeMAB5356, diluted 1:1000 in Odyssey blocking buffer). Note that thisantibody detects both canine and human RHO. Due to loss of glycosylationat Asn2, mutant T4R rhodopsin can be differentiated from WT (canine orhuman) RHO protein as it has a lower MW that can be detected onimmunoblots. RHO immunoblots from heterozygous mutant RHO^(T4R/+) thusshow two bands corresponding to WT (high MW), and mutant T4R (low MW)RHO proteins. Anti-histone H3 antibody (Abeam ab1791, diluted 1:3000)was used as a loading control and to normalize the signals.

Absolute Quantitation of Canine and Human Rhodopsin RNA in CanineRetina:

In order to determine the absolute amounts of both endogenous canineRhodopsin RNA and human RHO820 RNA present in the retina after treatmentwith AAV2/5-sc-HOP-RHO820-H1-shRNA820, absolute quantitation wasperformed using Q-PCR Standard Curve method. Dilution series of knownquantities of canine and human RHO cDNA were used to construct astandard curve. 0.1 nanogram of total cDNA was used for quantitation.Total amount of canine RHO and human RHO820 RNA in each sample wascalculated based on this standard curve.

FIGS. 19A-19F show RNA and protein analysis of rhodopsin knockdown andreplacement with AAV2/5-sc-HOP-RHO820-H1-shRNA820 injected subretinallyin mutant RHO^(T4R/+) dogs at 5×10¹¹ vg/ml titer. FIG. 19A shows retinalmaps showing position of biopsy punches used for western blot analysisand RNA quantitation. Paired dark gray, gray and dotted circles indicatethe position of biopsy punches in the treated (Tx) and untreated (UnTx)regions for each replication of western blot, whereas the black circlesindicate the position of biopsy punches for RNA quantitation. FIG. 19Bshows immunoblot showing the amount of total rhodopsin (canine+humanRHO820) in biopsy punches taken from treated (Tx) and untreated (UnTx)areas of canine retina. Histone H3 was used for normalization. Bargraphs show the percentage of remaining rhodopsin protein in the Treatedand untreated areas. Note the loss of the lower MW band (correspondingto mutant T4R RHO protein) in the treated areas of EM424-OD andEM425-OD. FIG. 19C is a table showing numerical values for each pair ofpunches used for protein quantification. FIG. 19D is a bar graph showingremaining canine Rhodopsin RNA in the treated areas as a percentage ofcanine RHO RNA levels measured in untreated to areas. FIG. 19E is a bargraph showing levels of human RHO820 in the treated areas as apercentage of canine RHO RNA levels measured in untreated areas. FIG.19F is a table showing numerical values for each pair of punches usedfor RNA quantification.

Evaluation by In Vivo Retinal Imaging of Photoreceptor Protection fromLight-Induced Damage in Eyes of Mutant RHO T^(T4R/+) Dogs InjectedSubretinally AAV2/5-Sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹ vg/ml:

Eyes from 2 mutant RHO T4R/+ dogs that were subretinally injected withviral titer of 5×10¹¹ vg/ml were examined by cSLO/OCT imaging beforeinjection, 11 weeks post injection (before light exposure), and 2 weekspost light-damage. A 1 min exposure to white light at an intensity(corneal irradiance of 1 mW/cm2) previously shown to cause acute retinaldegeneration in RHO T4R mutant but not in WT dogs was used to assess thelevel of protection conferred by the AAV2/5-sc-HOP-RHO820-H1-shRNA820vector in the treated/bleb area. ONL thickness in the bleb/treated areawas preserved at all post-injection time points suggesting that thisvector construct was not toxic and that there was no loss ofphotoreceptors during that period. The surrounding non bleb/untreatedregions were used as an internal control for each eye. Two weeks postlight-exposure there was complete preservation of ONL thickness in thebleb/treated area in both injected eyes.

FIGS. 20A-20C show in vivo retinal imaging showing protection fromlight-induced retinal degeneration in the region of a mutant RHO^(T4R/+)retina treated with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹/vg/mltiter. FIG. 20A shows en face cSLO composite showing 2 weeks post lightexposure the retinal region (border demarcated by white arrows) that wasprotected from degeneration. Light gray arrow indicates the locationwithin the treated area of the OCT B scans shown in FIG. 20B, dark grayarrow indicates the location within the untreated area of the OCT Bscans shown in FIG. 20C. FIG. 20B shows OCT B scans within the treatedarea before injection. 11 weeks post injection, and 13 weeks postinjection/2 weeks post light exposure. ONL thickness is preservedthroughout the treated area at both time-points following the injectionof the viral vector. FIGS. 20B and 30V show OCT B scans within theuntreated area before injection, 11 weeks post injection, and 13 weekspost injection/2 weeks post light exposure. ONL is preserved up to 11weeks post injection but is completely lost 2 weeks after lightexposure. FIG. 21 shows topographic maps of ONL thickness from a twoRHO^(T4R/+) treated with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at5×10¹¹/vg/ml titer showing to protection from light-induced retinaldegeneration.

Evaluation by Histology and Immunohistochemistry of PhotoreceptorProtection from Light-Induced Damage in Eyes of Mutant RHO^(T4R/+) dogsInjected with AAV2/5-Sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹ vg/ml Titer:

Eyes from the same mutant RHOT4R/+ dogs listed in above that weresubretinally injected with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at5×10¹¹/vg/ml titer and subsequently light exposed (at 11 weeks postinjection) to 1 min duration of white light at an intensity (cornealirradiance of 1 mW/cm2) were examined. This dose of light was previouslyshown to cause acute retinal degeneration in RHO T4R mutant but not inWIT dogs.

Immunohistochemistry was used to assess the level of protectionconferred by AAV2/5-sc-HOP-RHO820-H1-shRNA820 in the treated/bleb area.The surrounding non bleb/untreated regions were used as an internalcontrol for each eye. Antibodies directed against rhodopsin (RHO), andhuman cone arrestin (hCA) were used to assess the integrity of rod outersegments and cone morphology. Two weeks post light-exposure excellentpreservation of ONL thickness was achieved in the bleb/treated area ofeyes injected with the 5×10¹¹ vg/ml titers. In addition and contrary towhat was seen when treating retina with the knockdown reagent shRNA820,preservation of rod outer segments was achieved with theAAV2/5-sc-HOP-RHO820-H1-shRNA820 construct.

FIG. 22 shows immunohistochemistry (Rhodopsin was stained in green andappears as the lighter staining in the panels of FIG. 22; human conearrestin was stained in red appears as the gray staining in the panelsof FIG. 22) in the treated, transition zone and untreated areas ofmutant RHO^(T4R/+) retinas subretinally injected withAAV2/5-sc-HOP-RHO820-H1-shRNA820 at 5×10¹¹/vg/ml titer. In the treatedarea there is complete preservation of the outer nuclear layer (ONL)thickness, and of rod outer segments (OS), while in the untreated areaall rods have been lost and the ONL is reduced to a single row of conecell bodies. A clear boundary between treated and untreated areas isseen at the transition zone.

Complete knockdown of canine RHO RNA and protein (by western blot) isachieved with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at a viral titer 5×10¹¹vg/ml. Efficient replacement with hardened RHO820 is achieved both atthe mRNA (118-130%) and protein (30-33%) levels when compared to normalRHO levels in the canine retina. Complete protection of the outernuclear layer (ONL) which contains the cells bodies of thephotoreceptors is achieved with AAV2/5-sc-HOP-RHO820-H1-shRNA820 at aviral titer 5×10¹¹ vg/ml.

Complete preservation of rod outer segments as a result of efficient RHOreplacement with RHO820 is achieved withAAV2/5-sc-HOP-RHO820-H1-shRNA820 at a viral titer 5×10¹¹ vg/ml.

REFERENCES

-   1. Mao H, Gorbatyuk M S, Rossmiller B, Hauswirth W W, Lewin A S.    Long-Term Rescue of Retinal Structure and Function by Rhodopsin RNA    Replacement with a Single Adeno-Associated Viral Vector in P23H RHO    Transgenic Mice. Hum Gene Ther. 2012; 23:356-366.-   2. Rossmillcr B, Mao H, Lewin A S. Gene therapy in animal models of    autosomal dominant retinitis pigmentosa. Mol Vis. 2012;    18:2479-2496.-   3. Gorbatyuk M. Justilien V, Liu J, Hauswirth W W, Lewin A S.    Suppression of mouse rhodopsin expression in vivo by AAV mediated    siRNA delivery. Vision Res. 2007; 47:1202-1208.-   4. Khvorova A, Reynolds A, Jayasena S D. Functional siRNAs and    miRNAs exhibit strand bias. Cell. 2003:115:209-216.-   5. Reynolds A. Leake D, Boese Q, Scaringe S, Marshall W S,    Khvorova A. Rational siRNA design for RNA interference. Nat    Biotechnol. 2004; 22:326-330.-   6. Jensen S M R, Schmitz A. Pedersen F S, Kjems J+, Bramsen J B.    Functional Selection of shRNA Loops from Randomized Retroviral    Libraries. PLoS ONE. 2012; 7:e43095.-   7. Zhou H. Xia X G, Xu Z. An RNA polymerase II construct synthesizes    short-hairpin RNA with a quantitative indicator and mediates highly    efficient RNAi. Nucleic Acids Res. 2005; 33:e62-e70.

EQUIVALENTS

While several inventive embodiments have been described and illustratedherein, those of ordinary skill in the art will readily envision avariety of other means and/or structures for preforming the functionand/or obtaining the results and/or one or more of the advantagesdescribed herein, and each of such variations and/or modifications isdeemed to be within the scope of the inventive embodiments describedherein. More generally, those skilled in the art will readily appreciatethat all parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the inventive teachingsis/are used. Those skilled in the art will recognize, or be able toascertain using no more than routine experimentation, many equivalentsto the specific inventive embodiments described herein. It is,therefore, to be understood that the foregoing embodiments are presentedby way of example only and that, within the scope of the appended claimsand equivalents thereto, inventive embodiments may be practicedotherwise than as specifically described and claimed. Inventiveembodiments of the present disclosure are directed to each individualfeature, system, article, material, kit, and/or method described herein.In addition, any combination of two or more such features, systems,articles, materials, kits, and/or methods, if such features, systems,articles, materials, kits, and/or methods are not mutually inconsistent,is included within the inventive scope of the present disclosure.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

All references, patents and patent applications disclosed herein areincorporated by reference with respect to the subject matter for whicheach is cited, which in some cases may encompass the entirety of thedocument.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined. i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one embodiment, to A only (optionally including elements other thanB); in another embodiment, to B only (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of,” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

It should also be understood that, unless clearly indicated to thecontrary, in any methods claimed herein that include more than one stepor act, the order of the steps or acts of the method is not necessarilylimited to the order in which the steps or acts of the method arerecited.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively, as set forth in the United States Patent Office Manual ofPatent Examining Procedures, Section 2111.03. It should be appreciatedthat embodiments described in this document using an open-endedtransitional phrase (e.g., “comprising”) are also contemplated, inalternative embodiments, as “consisting of” and “consisting essentiallyof” the feature described by the open-ended transitional phrase. Forexample, if the disclosure describes “a composition comprising A and B”,the disclosure also contemplates the alternative embodiments “acomposition consisting of A and B” and “a composition consistingessentially of A and B”.

What is claimed is:
 1. A synthetic ribonucleic acid (RNA) moleculecomprising: a) a sense strand of sequence CUGCCUACAUGUUUCUGCU (SEQ IDNO: 1) and an antisense strand of sequence AGCAGAAACAUGUAGGCAG (SEQ IDNO: 2); b) a sense strand of sequence CCUACAUGUUUCUGCUGAU (SEQ ID NO: 3)and an antisense strand of sequence AUCAGCAGAAACAUGUAGG (SEQ ID NO: 4);c) a sense strand of sequence GCAUGGUCAUCAUCAUGGU (SEQ ID NO: 5) and anantisense strand of sequence ACCAUGAUGAUGACCAUGC (SEQ ID NO: 6); or d) asense strand of sequence GUGGCAUUCUACAUCUUCA (SEQ ID NO: 7) and anantisense strand of sequence UGAAGAUGUAGAAUGCCAC (SEQ ID NO: 8).
 2. Thesynthetic RNA molecule of claim 1, wherein the RNA is a smallinterfering RNA (siRNA).
 3. The synthetic RNA molecule of claim 1,wherein the RNA is a small hairpin RNA (shRNA).
 4. The shRNA of claim 3,having a loop that comprises RNA of sequence UCAAGAG (SEQ ID NO: 9) orRNA of sequence UGUGCUU (SEQ ID NO: 10).
 5. The synthetic RNA moleculeof claim 1, wherein the RNA is an artificial micro RNA (miRNA).
 6. Theartificial miRNA of claim 5, wherein the artificial miRNA comprises RNAof sequenceUGCUGUUGACAGUGAGCGA(X)_(n)UAGUGAAGCCACAGAUGUA(Y)_(n)CUGCCUACUGC CUCGGA(SEQ ID NO: 19), and wherein: a) (X)_(n) comprises SEQ ID NO: 1 and(Y)_(n) comprises SEQ ID NO: 2; b) (X)_(n) comprises SEQ ID NO: 3 and(Y)_(n) comprises SEQ ID NO: 4; c) (X)_(n) comprises SEQ ID NO: 5 and(Y)_(n) comprises SEQ ID NO: 6; or d) (X)_(n) comprises SEQ ID NO: 7 and(Y)_(n) comprises SEQ ID NO:
 8. 7. The synthetic RNA of any one ofclaims 1-6, further comprising an unpaired overhang sequence at the 5′and/or 3′ end.
 8. The synthetic RNA of claim 7, wherein the unpairedoverhang sequence comprises a sequence of repeating bases.
 9. Thesynthetic RNA of claim 8, wherein the sequence of repeating basescomprises repeating uracil (U) bases.
 10. The synthetic RNA of claim 9,wherein the unpaired overhang sequence is UU.
 11. A compositioncomprising the synthetic RNA of any one of claims 1-10.
 12. Thecomposition of claim 11, further comprising one or more physiologicallyacceptable carriers and/or one or more physiologically acceptableadjuvants.
 13. A vector encoding: a) the shRNA of claim 3 or 4; or b)the artificial miRNA of claim 5 or
 6. 14. The vector of claim 13,wherein the shRNA is selected from any one of SEQ ID NOs: 11-18.
 15. Thevector of any one of claims 13-14, wherein the vector is an expressionplasmid.
 16. The vector of any one of claims 13-15, wherein the vectoris a viral vector.
 17. The viral vector of claim 16, wherein the viralvector comprises an adeno-associated viral vector.
 18. A method ofdecreasing RHO expression in a subject, the method comprisingadministering to the subject the composition of claims 11-12 or thevector of claims 13-17.
 19. A method of treating retinitis pigmentosa(RP) in a subject, the method comprising administering to the subjectboth: a) the composition of claims 11-12 or the vector of claims 13-17;and b) a recombinant RHO gene that does not contain a sequence targetedby an interfering RNA of the composition or the vector of a).
 20. Themethod of claim 19, wherein the recombinant RHO gene is delivered usingan rAAV.
 21. The method of claim 20, wherein the interfering RNA and therecombinant RHO gene are delivered using the same rAAV.
 22. The methodof claim 21, wherein the interfering RNA and the recombinant RHO geneare both under expression control of a single promoter sequence.
 23. Themethod of claim 22, wherein the interfering RNA and the recombinant RHOgene are each under expression control of independent promotersequences.
 24. The method of claim 23, wherein the interfering RNA isshRNA, and wherein the shRNA is under expression control of an RNApolymerase III promoter.
 25. The method of claim 23, wherein theinterfering RNA is an artificial miRNA, and wherein the artificial miRNAis under expression control of an RNA polymerase II promoter.
 26. Themethod of claim 24 or 25, wherein the recombinant RHO gene is underexpression control of a constitutive or inducible promoter.
 27. Themethod of any one of claims 19-26, wherein the subject is a mammal. 28.The method of claim 27, wherein the mammal is a rodent or a dog.
 29. Themethod of claim 27, wherein the mammal is a human.